small leak at coolant bottle

jdulle

Veteran Member
Joined
Feb 4, 2017
Location
Ithaca, NY
TDI
96 B4, 97 B4
I have a 96 B4, and am noticing a small amount of coolant coming out of the coolant bottle at the overflow rectangles about 2/3 of the way up the bottle. I am hoping its not a head gasket problem. No evidence of oil in coolant or coolant in oil yet. Also not too much steam in exhaust. I am thinking first step is replacing the cap. I guess I should either run it with the cap off to look for bubbles, or run for a couple mins and try opening cap to see if a lot of air escapes before it gets hot. Anything else to look for?
 

ToddA1

Top Post Dawg
Joined
Aug 3, 2011
Location
NJ 08002
TDI
'96 B4V, '97 B4 (sold), '97 Jetta (scrapped)
Sounds like it’s either the cap or cap gasket.

-Todd
 

jdulle

Veteran Member
Joined
Feb 4, 2017
Location
Ithaca, NY
TDI
96 B4, 97 B4
I tried opening the cap after it had been running for a minute and no pressure buildup, so am hoping its the seal. The cap wasn't too expensive so I just got that instead of only the seal. I probably should get a bottle too, because I can't see the level of the coolant through the cloudy plastic.
 

Steve Addy

Top Post Dawg
Joined
Aug 7, 2002
Location
Iowa
TDI
97 Mk3
I tried opening the cap after it had been running for a minute and no pressure buildup, so am hoping its the seal. The cap wasn't too expensive so I just got that instead of only the seal. I probably should get a bottle too, because I can't see the level of the coolant through the cloudy plastic.
I hate to ask but what color is the 'cloudy' part?

Steve
 

jdulle

Veteran Member
Joined
Feb 4, 2017
Location
Ithaca, NY
TDI
96 B4, 97 B4
So the bottle itself looks fairly white, but you can't see the level of the coolant through it. Inside the coolant looks a little rusty, and is an orange color. It does have either G12 or G11 coolant in it. I think the coolant was changed fairly recently because it has a new water pump, but probably the bottle was not cleaned out at the time. I put the new cap on but have not driven it yet to check it.
 

Steve Addy

Top Post Dawg
Joined
Aug 7, 2002
Location
Iowa
TDI
97 Mk3
There are some issues with adding certain coolants to older type coolants. This chart should be posted somewhere in a sticky just for reference. If you're starting clean with coolant at some point, which it sounds like you might want to, then just get the G13 and you'll be fine.

Steve

 

jdulle

Veteran Member
Joined
Feb 4, 2017
Location
Ithaca, NY
TDI
96 B4, 97 B4
The previous owner put in fresh coolant when he replaced the water pump 1.5 yrs ago and he gave me a couple extra jugs of the coolant. I think it was G12. So I think what is in there is all one type, luckily. I will go to the g13 next time I buy some. thank you!
 

Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
Do a leak down test if you have not solved this yet. Typical issue is the head is warped but not bad enough for normal driving, when at boost it can displace the coolant via overcoming the head gasket and head studs clamping pressure.

You need to do about a dozen hard pulls for extended time, like 30 seconds each, then pull the cap and check for excessive pressure. If this is the issue, pulling the head, having it decked and specking the block is the ONLY correction that works permanently. I for one have had this issue and this is how it’s fixed. Don’t take it to a machine shop unless it’s a reputable VW TDI shop for this job. I highly suggest paying up and have Franko6 do your head work
Frank's VW TDI's, LLC
1007 Olive St.
Lockwood, MO 65682
417-232-4634
FranksTDIs@sbcglobal.net


Do you have any mods? What PSI are you running?
Let’s put it this way, when an engine is properly built, you can easily get 35 to 40psi with no head lift what so ever.
I’m here with you on this issue. I had my head decked and upgraded to undercut valves and springs, port and polish etc... And I still have this issue; I found out that it’s an issue with the block in my case. You need to measure the block deck against each main bearing journal. If your pistons and rods are in spec and undamaged you can measure the block from the piston and just do the math and subtract. I don’t have the specs on me for piston high,
Also what whole size gasket is on your TDI, look at the gasket and see how many round holes are present vs oval holes. This gives you a critical measurement on the piston height vs the head and you must machine to patch this gasket if you change it.
ARP head studs are problematic as well. Many owners try and swap them and have this issue. Unless your building a high end, stick with PD head studs if you swap them.

As far as the coolant, yea there is great debate here on "don’t mix" or "don’t use the wrong one" yea that’s all honestly subjective and to each owner to decide what to run but in my two cents, it makes no difference. The silicate content was an issue in the past but has since been solved. I have ran 3 separate coolant types in my vw and never seen any issue. What we are all talking about is life of the coolant and the parts. I’m sure that the ones who argue to only use the right stuff are correct in making parts last 200K miles between coolant changes but honestly there are few and far between TDI's that go 150K or 200K miles without cracking open the coolant system and thus makes no difference on what you run, I do agree that you should not mix anything that is not rated to mix but as long as it’s all the same coolant, it’s all good and you can do much worse harm to the engine with other things vs coolant.
 

Steve Addy

Top Post Dawg
Joined
Aug 7, 2002
Location
Iowa
TDI
97 Mk3
The previous owner put in fresh coolant when he replaced the water pump 1.5 yrs ago and he gave me a couple extra jugs of the coolant. I think it was G12. So I think what is in there is all one type, luckily. I will go to the g13 next time I buy some. thank you!
If you have a couple jugs of G12 or G12+ then you'll be set for a while.

Steve
 

jdulle

Veteran Member
Joined
Feb 4, 2017
Location
Ithaca, NY
TDI
96 B4, 97 B4
So the bottle I have says G13, and I think that is what is in there, so that's good. I will try some hard pulls to see if that makes the bottle weep. I did just drive it for 30 miles, but didn't do any full throttle driving. The bottle looked totally dry. It is totally stock at the moment. I may do a malone stage one, but I am going to keep the car close to stock. Plenty of power for me as it is. If it only happens at full throttle, I probably won't take it apart to do the head right away.
 

Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
My AHU as i stated before has this issue. here is how it works for me. i can drive 500 miles non stop if i wanted to but when i get onto a long tall mountain climb i will climb in heat if not careful. temps stay 185 all day long but if i go up a mountain pass ill climb up to 220, once i pass 220 it will skyrocket up to 230, then 240 and bam, I can take care of it by being easy up those roads, highway is no issue even at 85mph. I go autocross with it WOT all as much as i can and do not let up on the car and after 8 runs i dont even have much lost, like a little wetness but runs all day. Autocross is not hard on the engine like a hill climb though. you need to punish the boost levels to test it. I cant race it on the streets or anything more than a quick hard pull once or twice otherwise i have issues. ill fix it but its parked for the year and only used for going to meet ups and autocross events.

video link to my autocross runs, good idea of what i can get away with in abuse with no issues of boiling it over.

https://www.youtube.com/watch?v=soqc0Ye0hgo

https://www.youtube.com/watch?v=zCXDiHKGsjQ

https://www.youtube.com/watch?v=BZWX8yO3cgE
 

jdulle

Veteran Member
Joined
Feb 4, 2017
Location
Ithaca, NY
TDI
96 B4, 97 B4
I haven't done any big mountain passes with this car yet. It always stays at 185. I will try a drive doing some full throttle runs and if the bottle doesn't leak that's good enough for me. I don't drive it hard, but I realize its important to use the boost to keep the turbo seals in place. Its also hard to drive this car slowly, it wants to go fast.
 

Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
There is no such thing as turbo seals, there are o rings on the intake pipe on some cars and the output from the turbo on some other cars, but i dont think thats what you meant. VW turbos are all (for the most part) journal bearing. no seals, meant to leak oil, thats how they work.

You want to give tdi's some hard pulls now and again just to keep crud from building up and for the turbo shaft, cam, gears, rings, and what not some wear across the board. this is also true of most engines in civilian transportation.

Honestly the best thing for you to do is to rule out all other variables. Do a leak down test see what comes up
 

iluvmydiesels

Veteran Member
Joined
Nov 21, 2015
Location
phila area
TDI
AHU
turbos have seals right, not usually a problem. keep oil flowing in engine/ and turbo and its usually fine. as long as its changed properly and good,new oil filter.
 

Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
turbos have seals right, not usually a problem. keep oil flowing in engine/ and turbo and its usually fine. as long as its changed properly and good,new oil filter.
what are these seals you speak of? VW turbos are mostly all journal bearings, No seals. oil quality does not make much difference, i mean who judges the oil quality for the turbo and not the engine.
The only thing to worry about on turbos oil flow is the amount it gets and if its had time to cool off and not heat soak and cook the oil. This is only a issue for aftermarket or turbo upgrades.
can you explain what you are talking about here?
 

iluvmydiesels

Veteran Member
Joined
Nov 21, 2015
Location
phila area
TDI
AHU
we have to be on different pages. who said i 'judged' oil differently for a turbo than other internals? although a turbo is more 'fragile'(if you will). so not maintenancing oil properly, the turbo may well be first, most likely effected. and yes a higher quality oil definitely should perform better. (when use properly do not put a high quality oil in an engine case for the first time at high-mileage <very important point).
cooking or scalding oil is a fairly immature way of operating a/your vehicle. most stock set-ups this will not happen. perhaps in an extreme, like a very long,steep hill at very high speeds, and be like you get to the top and shut motor off. -for aftermarket, the more turbo work, yes it can come into play, &/or with quite a bit more engine power,performance. then again if you built it, or had a good shop build it, you must know it/when oil gets that hot. or your shop made you aware of what that type of situation is.
where in my above post did i make a differentiation between oil in a turbo and an engine?
why would you even imply a high(er) quality oil doesnt make a difference, isnt that 'kind-of' the idea?
one of the things i outlined was changing oil at proper intervals, a good point, if oil is old, or perhaps,&, has impurities, like soot, and such, flowing, wouldnt you mark the turbo to most likely to be the first, and perhaps most effected. kind of obvious, at least to me. idk.
 

jdulle

Veteran Member
Joined
Feb 4, 2017
Location
Ithaca, NY
TDI
96 B4, 97 B4
I'll have to do a leak down test eventually, I don't have the tools to do that myself, but for now I am going to try some full throttle runs and check the bottle, and also keep an eye on the coolant and the oil.
 
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