1.6NA Oil Blowing Out Dipstick Tube

Diesel_Aggie

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I hope my 1.6NA question is welcome here! I have an '81 Caddy with a 1.6NA diesel that recently started blowing oil out of the dipstick tube. Mileage is unknown and the year of the 1.6 is unknown but it is mechanical valves. I bought the truck 2 years ago. It sat for most of the first year and has been driven for the last year. The last 6 months it has been a daily driver. Oil consumption has been a quart every 1200-1500 miles prior to latest problem. At 60-70mph at 3600' elevation there has always been light smoke blowing from the tailpipe going uphill or into a headwind. Seems to be black diesel smoke. Starts up great in single digits. 5000 miles back I switched to Rotella T 5W-40 synthetic. It was about 3000 miles into this the oil started coming out the dipstick. It did it once on a 700 mile highway trip and stopped. I didn't know where the oil was coming from so i cleaned it up and it didn't leak for maybe 1000 miles or so. Drove it to Dallas and it started leaving big oil drips on the ground. Suspected the dipstick, cleaned the area and confirmed. Changed oil/filter today, cleaned and after driving 5 miles you could see oil streaming down the dipstick. Pulled the crankcase vent hose from the valve cover to airbox. It is not obsctructed but is wet with oil. Started engine with line removed from valve cover. Lots of blowby coming out of this hole and out of dispstick. You can see the oil drops coming out of the dipstick but not the valve cover. Pulled the hose from the vacuum pump to the engine block at the vacuum pump side. Tons of blowby comes out of here when it is off. When it is off the quantity of oil coming out of the dipstick is less as is the blowby out of the valve cover and dipstick. Plug is with your finger and it goes back thru the other areas.
I spoke with Parts Place Inc. briefly and they suggested trying a German oil filter instead of the Napa Gold/Wix I've been using. I'll get one this afternoon but I've been running the same filters for the last 15,000 miles with no issues until now. They also suggested that there is a port/vent on the oil pump that may be clogged. Can anyone elaborate on this and what to look for? My Bentley is not with me unfortunately. Parts Place felt that it was not rings as I was worried about and said to put a manual oil pressure guage on it. I'll try and find a guage this afternoon as well. Truck starts immediately and seems to have normal power. I do not have the extra under valve cover piece that I have seen discussed in some forums. I can believe that the switch to synthetic freed up a bunch of crap in the engine and that it is plugging something up.

What is causing the oil to blow out?

Where do I put the manual oil pressure guage on the engine?

What do I look for on the oil pump?

What is the purpose of the tube from the engine block to the vacuum pump?

Thanks for the help.
 

Diesel_Aggie

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I was wondering if it could be re-ringed in the car. That is great news. What are I-shaft bearings? I'm familiar with crank bearings, rod bearings and piston pins. If I drop the crank, rods and pistons out the bottom does this mean I leave the headgasket alone? I wasn't clear if you just look at the number of tabs on the current head gasket an order the same or if you have to measure the protrusion of the pistons above the block and calculate what gasket to use. The measuring/calculating scares me.
 

oilhammer

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There are just too many to list....
I-shaft is the Intermediate shaft in the block that turns the oil pump and vacuum pump. It only has 2 bearings, one at each end. If those are worn, the shaft will need to come out, and that means the engine needs to come out.

Those mains are rarely worn much. You can remove the head, take the rods and pistons out, get a valve job, rering the pistons, and put it back together provided the cylinder walls are not in too bad of shape.
 

Diesel_Aggie

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I put a manual oil pressure gauge ($19.99 Harbor Freight special) on the fitting on the driver side of the cylinder head. Oil pressure is 85-90psi at idle with 80 degree weather on Rotella T 5W-40 synthetic. Revving the engine to maybe 1500-1800rpm makes the pressure rapidly rise past the max 140psi line back around to the stop. Found a Bentley and read about the pressure relief valve on the oil pump. Section 5 page 33 figure 6-1 if this helps anyone in the future. Now the question is are bad rings causing the excessive oil pressure or is it the relief on the oil pump? I'll do a compression test on Friday since I'm about out of daylight now and don't have new injector crush washers. Either way it's a pretty cheap fix as long as I don't have to go to oversize pistons.
 

oilhammer

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There are just too many to list....
Yes, there is a check valve in the oil pump. However, I would slap a new oil pump in there when you do the rering anyways.

Compression test really will not give you much to go on in regards to blow-by. It will still probably test good.
 

coalminer16

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I would say it is either blow by or a plugged vent. There is a screen in the valve cover that could have really oil sluggish oil in it and it isn't allowing it to breath into the air filter housing. It would be a cheap try to just take it out and put in solvent for a while to clean it out. While you are in there put a plastic splash gaurd in to help prevent your engine from running away. Which is where the oil fumes get sucked through your vent pipe in the the intake (I have gaurds in all my engines just in case). Compression test should tell you some interms of how worn your engine is. If you are going to commit to the rebuild parts place does have a good kit to rebuild everything. Find someone to bore your engine and get the 3 notch head gasket so you don't have to worry about the measuring of the piston above the block. Get the pre ground intermediate shaft bearings. They are two sizes. The smaller one is on the tranny side. Always replace the oil pump. Replace all the seals. Replace the top valve cover gasket with a rubber one. Change you timing belt (I would do that if you haven't already, and the tensioner pulley).
It would be a good time to do the clutch and throughout bearing and upgrade to a newer style vaccum pump (a vane pump). That way you don't have to rebuild your vaccum pump every year or two. I can help you if you need on your truck as I have two 81's (truck, 4 door car) and have working a lot on both including my brothers 80 truck.
tgott@hotmail.com
Hope it all goes good. You don't have to rebuild the engine though mostlikely. Just find why it is blowing by. You can take the engine out and in without an engine hoist but it is better with one. Get new engine mounts as well if you do rebuild everything. Here is a link that may help you
http://www.4crawler.com/VWpickup.shtml
This guy has done it all and then wrote about it. He even makes some nice upgrades (shifting linkage and leaf spring bushings for the truck and a tach)
 

PDJetta

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I would say the rings and bores are worn out. But, I would check the crankcase breather first, as suggested above. It could be that too.

I had really poor results when I honed and re-ringed my 1.6 liter ('85) Jetta TD. I got about 20,000 miles out of it before it began burning about a quart of oil every 300 miles. Then I put a "rebuilt" engine in it and got about the same 20,000 miles out of that before the engine consumed a quart in 300 miles. I later found out the guy I bought the motor from did the same thing--a hone and re-ring. The block was worn out I suspect on both of these engines and the hone I did made it worse, I think. Moral of that story is to check the bores in the block against the wear limits given in Bentley and if too worn, or out-of-round, you must go to oversize pistons and the block must be pulled for boring at a machine shop, otherwise, you get what you pay for.

If you like I can pull out my Bentley for the 1.6 L diesel and give you the bore wear limit and piston-bore clearances, just send me a PM if you want these tolerances.

--Nate
 
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oilhammer

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There are just too many to list....
It is true, a simple hone and rering usually will result in some oil burning, but you will get the blowby back under control and the engine will run just fine.

Since diesels won't foul spark plugs, and the older ones do not have catalysts, oil burning is not that big of an issue so long as you keep after it. Nice thing too is these engines hold a lot of oil for their size.

If you are burning lots of oil, you just never change it. Spin a new filter on every 20k miles or so and motor on. :p ...I know, I got over 400k miles out of a Mazda! :D
 

Diesel_Aggie

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Got busy fixing the fuel starvation problem on my dually and never got the compression numbers posted. I think I have my cylinder numbers backwards....I started testing on the passenger side of the engine and am considering that number 1.

1-460
2-480
3-520 checked it twice thinking I screwed up
4-400

Bentley says compression should be between 398-483psi. Anything below 398psi or 2 cylinders next to each other with over a 71psi difference calls for a tear down. The 520 is what confuses me. I guess there is carbon buildup on the piston for that cylinder? Only thing I can think of.

coalminer16- Thanks for the tips, especially the headgasket. Hypothetically speaking, if I go with the 3 tab that I understand to be the thickest and if I measured my engine and it called for a one tab, am I not losing compression ratio? Is it a significant amount or not enough to even worry about? Three tab is probably my best choice as I don't really know how to measure this and don't trust myself.
 

oilhammer

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There are just too many to list....
You need to use the correct head gasket. Generally, using the same as what you took off is fine. It is tough to measure piston potrusion acurately.
 

PDJetta

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You have the cylinder numbers correctly. #1 is at the pulley/pump/belt end of the engine.

--Nate
 

v8volvo

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oilhammer said:
You need to use the correct head gasket. Generally, using the same as what you took off is fine. It is tough to measure piston protrusion accurately.
+1 on this. If you want it to start and run properly, esp in cold weather, you need as much squeeze as you can get. Settling for the 3 notch if the engine really wants a 2 or 1 will have consequences in power, emissions, economy and driveability and will make it a lot harder to get it going on a cold morning, particularly as the motor ages and the miles pile up....

(If in doubt, though, just use what it had before... using a 1-notch on a 2-notch engine is a lot worse than using a 3-notch on a 2-notch engine, for reasons that should be obvious... :eek:)

However, all that said, I think the gasket discussion may be moot because I doubt the rings are actually your problem. Your compression numbers are pretty good, well above the point where these usually start blasting oil out the dipstick or running away (the other, much worse thing that can happen to engines showing symptoms like yours). With numbers above 400 blowby is probably not your problem -- these often can get down to around 280-300 and still run OK (though tough to start). I think it's more likely you have a plugged crankcase vent system somewhere. Easier to check that than to pull the head, so try going through the breather system completely first.

You may try posting here: www.vwdieselparts.com/forum . This is a great group dedicated only to the older IDI VW diesels like yours. Occasionally people come on there asking about your problem, and there is always a solution...

Good luck! If it does come to a re-ring, I will contradict the statements of others on here and say that mine has gone 25,000 miles since I did a very quick and cheap re-ring on a pretty tired engine, with zero blowby or oil use to this day. They don't last like a rebuild will, but if you are on a tight money and time budget they are great to get you back on the road for at least a few more years. Then it's time to swap in a TD. :cool:
 

coalminer16

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Just to clarify it really doesn't matter according to several people that deal with the older vws on if you put a 3 notch in the car. You may lose a couple psi (which your cyliners are off more then that). It is better to lose compression then to crash the piston into the head. Also the vw engine was diesigned too start in cold temps -30F without issues (fuel and timing matter here the most along with working glow plugs). But the engine runs (according to some) best and most efficiently at 17:1 instead of the 23:1 factory. Some people do lower there compression for that reason. The differences in the thickness of gaskets are about .002 or .003 inches. So if all of you think that matters that much on the engine let me know why so I can inform the others that have misinformed me. If your engine has a 1 notch and you didn't change pistons, rods, main bearings or anything that would affect piston throw/protrusion from the block then use the same notch when replaceing just the gasket. If you rebuild your engine you can put it together, measure, order correct gasket (and hope you measured correct), wait for the ordered gasket to arrive, then install or just get a 3 notch at the start of rebuild and be done with it. I would say that you still could have some blow by (as number 4 was on the lower end of the spec). Either way something has to be entering the engine on the lower end to add pressure to it. Heat alone won't cause those results as there is a breather that leads into the air filter box that is suppose to release any pressure. Which leads me to the question of did you check the mesh filter in your valve cover yet and is it clean?
For the record between my brother's vw and the 3 of my engines I have (one I totalled rebuilt). All have started just find in -20/-30F weather and with good glow plugs, proper timing and ungelled fuel and a strong battery you can start the first crank everytime even when sitting for a month or two. I have done it as I rotate through my cars (park one for a month take insurance off, put insurance on other and drive). I had to fix my brothers timing as the previous owner didn't time it very well. Now it also starts like a champ.
A few more things maybe. Is there fuel in the oil as an injector could be bad and spraying past the piston (happens on the large CAT engines) and it may be a cheaper/incorrect fuel that is vaporizing when it gets warm enough (diesel engines are warmer then gas engines most of the time). Just thoughts.
 
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oilhammer

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There are just too many to list....
Why would they have engineered them with different thickness headgaskets if it did not matter? VW could have saved literally millions of dollars over the years, but they didn't. It is not hard to use the correct one. Why try and out think the engineers on something so simple? :rolleyes:
 

v8volvo

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It is true that, apart from cold-weather starting, the old diesels could run even a little better with slightly lower compression in cases where there is something to fill that extra space with more air (turbocharger). However, if you want to lower compression, the only appropriate and effective way to do it would be to somehow increase the size of the prechambers. Increasing volume between the piston crown and the head surface, outside of the prechamber, will only have negative effects on performance and efficiency. And really on a diesel the only reason you'd ever want *lower* compression would be in order to cram in more air on a turbocharged engine when cranking up the boost. No turbo on this, so you're best off with maximal compression.

Sure it'll run with the wrong gasket.... but it won't run as well as it could. Getting the right gasket in is the easiest performance helper you can do on this engine, assuming you're replacing it anyway...
 

coalminer16

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oilhammer said:
Why would they have engineered them with different thickness headgaskets if it did not matter? VW could have saved literally millions of dollars over the years, but they didn't. It is not hard to use the correct one. Why try and out think the engineers on something so simple? :rolleyes:
Because I am an engineer. Not to mention deal with diesel engines daily at work. Have you ever heard of over engineered and also "looks good on paper". I don't think they would have saved millions on this. They wanted a reliable starting engine. If it mattered SO much then why can the engine specs be so far off. Also I am sure the must have weighed each piston and rod and checked the spring force of each valve spring. Not to mention make sure each injector has the same injecting properties (spray pattern, amount, etc). Also how do we now that they didn't just use the gasket to compensate for all of these factors. Remember how many computer models existed then to check these theories on how engines worked. Also how many computers were on the engines adjusted the engine functions like today's TDI's and other TIER rated engines. So maybe they compensated. I doubt being that this engine is so close to being out of spec that a thicket head gasket will really make a difference. If someone has positive proof that it will help the engine then by all means lets see it then. But unless you were a VW engineer no one will know for sure (including me). But I do know that it hasn't affected mine or any one elses engine I have talked with on the engine. Why risk crashing the head on the pistons if measure wrong. If nothing was don't to the engine you may see I didn't say go thicker did I. Back to the orginal question. Other then trying to prove a point on endless rants about proving me wrong why don't you offer more suggestions on what is wrong with this engine everyone as that is all I was attempting to do? Not saying that I know more on the 1.6 NA engine but that is my main driver for me (wife gets the 1.9 TDI) so I have worked a lot on the 1.6.
 
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oilhammer

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There are just too many to list....
I already did offer what I felt was wrong. :rolleyes:

And please, do not compare non-VAG diesels here. People get confused when they do so. Volkswagen engines are not like big road grader or OTR truck engines.

The head gasket is a non-issue for me, since it is so easy to do it correctly.

And yes, I have had to redo countless head gaskets on VAG diesels over the years from poor performance due to people simply slapping the thickest head gasket in place. It happens.
 

v8volvo

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Yep, not trying to get into an argument here but the fact is there is a reason it was done the way it was done. Maybe they will start and run OK with a fat gasket for the first little bit after the rebuild, while the engine is still tight, but get a couple hundred thousand miles down the road and the picture may be different... at very least, using a gasket that is too thick will make that time when the engine no longer starts on a cold morning due to low compression come that much sooner.

Using the part that gives the sloppiest tolerance in order to insure against screwing up without actually doing the precision work that is required is shade-tree logic. Using the right part that will provide the best performance is good engineering and good mechanicing. ;)
 

nokivasara

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If your intake has two crank vent hoses running to it then there's a easy way of getting the blow by pressures to a more normal level.

Take off the vent hoses and look in to the inlet manifold, there's a smaller orifice that restricts the flow of the vented gasses. You can drill them out to the same size as the hose and that will probably put an end to the oil creeping out of the dipstick tube.
This is not recommended if you have a lot of blow by through the rings since the engine could start running on it's own oil and self destruct, but since your compression is pretty good I don't think that will be a problem.
 
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coalminer16

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1.9 Gaskets
1 notch - 1.45mm
2 notch - 1.53mm
3 notch - 1.61mm

1.6 Mechanical Gaskets
1 notch - 1.4mm
2 notch - 1.5mm
3 notch - 1.6mm

1.6 Hydro Gaskets
1 notch - 1.53mm
2 notch - 1.57mm
3 notch - 1.61mm

So this is about .0039 difference in gasket thickness. and this is the how to measure according to vwcaddy.com Cylinder Head Gasket Selection On
1981-86 Volkswagen 1.6L (96.9 CID) Diesel Engines

The cylinder head gasket used in the 1981-86 Volkswagen 1.6L (96.9 CID) diesel engines is available in three thicknesses distinguished by notches on the side of the gasket. The correct gasket is selected by measuring piston protrusion on all four cylinders and basing the selection on the highest piston height.

Protrusin should be measured as indicated in the illustration below by using Volkswagen tools VW382/7 and VW385/17 or equivalents. It is important that your depth gauge/dial indicator set-up not rest directly on the piston itself to
prevent possible distorted readings. Parallels placed on the deck surface next to each cylinder will provide a good base for measuring.


For those that aren't shade tree mechanics. But I read in that forum that most go with the thicker. Must be a lot of bad running vw diesels out there including mine by the sounds of it. Also must be a lot of shade tree ones. Also I won't compare different diesel engines anymore since I gues the only thing in common is, diesel. Not that they have pistons, similar injection systems of the time period, a crank. I think there may even be valves and a head. To think of it, looking at the basics of even a gasser are similar. So I think you can compare some for trouble shooting.

Back to the thread which doesn't appear the original person has even looked at do any of you have advise to her problem and not my messed up wait of shad treeing things. I am going to say it would either be breathers or compression leaking in the cylinders. Maybe between the two not being fully correct with possible restriction in the breather and with just enough compression leaking into the crankcase that it is doing this. Also thinking there may be to much oil in the case. Adding a windage tray to the crankcase might help as the oil can't splash around as much then from the crank. But I guess I don't know much as I am too shady to work on these older engines.
 

coalminer16

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Appears that correct compression ratio from factory is 23:1 but each notch off according to the masses of shade tree mechanics it will lower it by to around 22.4:1 by being one notch off. Also one person had the wrong one on and had to much compression and it lost horse power till problem was fixed.
 

nokivasara

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I think that a thicker gasket may work pretty good, especially during summer but the larger squish area will make the engine harder to start when the temperatures drop. How much harder depends on the overall condition of the rest of the engine.
An IDI needs all compression it can get to start nicely :)
 

Diesel_Aggie

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The oil pump arrived last Friday but I've either been on the road or incorrectly doing Passat struts so I haven't had the chance to install it. Hoping to knock that out Saturday morning and see what happens. Found a rust free TDI Passat wagon so really need to get the truck together and sold now to fund that project.
 

Diesel_Aggie

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I installed the new oil pump assembly, oil pan and gasket last night. Got engine oil today and the problem appears to be solved. No oil blowing out the dipstick tube. After driving 30 miles there was a tiny bit of oil that had come out of the tube but i think that is because the dipstick is not a perfect fit anymore. Before at idle I could pull the dipstick out slightly and see oil spraying. Rev it up and it sprayed worst. Can't see any of that now. Found three small pieces of metal in the pan and one large piece of plastic. I'll post pics later. The woman just called from 2 hours away and said the B4 is not coming out of gear well if at all while running. Goes in fine. Claims normal pedal. Not sure if I have hydraulic, linkage or pressure plate issue.
 

Gold1.6

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I installed the new oil pump assembly, oil pan and gasket last night. Got engine oil today and the problem appears to be solved. No oil blowing out the dipstick tube. After driving 30 miles there was a tiny bit of oil that had come out of the tube but i think that is because the dipstick is not a perfect fit anymore. Before at idle I could pull the dipstick out slightly and see oil spraying. Rev it up and it sprayed worst. Can't see any of that now. Found three small pieces of metal in the pan and one large piece of plastic. I'll post pics later. The woman just called from 2 hours away and said the B4 is not coming out of gear well if at all while running. Goes in fine. Claims normal pedal. Not sure if I have hydraulic, linkage or pressure plate issue.
i was reading this post and was wondering if the pump was the fix
 
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