blown head gasket

KBCB

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Oct 14, 2015
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CO
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Blown head gasket. Now with pics!

Pretty sure I already know the answer but I figured I'd ask here before tearing the motor completely down.

As the title suggests I'm wondering if I have a bad headgasket or if there is something else I should check first.

Symptoms:
Erratic power when accelerating onto the highway.
Blowing white smoke out the tail pipe.

Did a compression test
cyl 1 cyl 2 cyl 3 cyl 4
360 460 400 400

when I pulled the glow plugs cyl 3 and 4 had white residue on the tip

When running (cold) I didn't see any bubbles in the coolant.

Like I said pretty sure I know the answer, but I want to be sure before tearing the motor down.

Thanks!
 
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Seatman

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Apr 23, 2010
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2014 Skoda rapid elegance 1.6 cr tdi
One common sign is coolant level dropping after a journey, that's something I really noticed on mine. No loss of power though, it'd need to be fairy bad for that to happen.
 

Henrick

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Golf VI TDI, 77 kW (CAYC)
I wouldn't be 100% sure this is head gasket.
Are your coolant hoses rock hard?
Any coolant loss?
 

Mongler98

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COLORADO (SE of Denver)
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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.
80% sure your head gasket is fine.
100% sure test is how hard the coolant line is after a full normal day commute after a few hard pulls, your inexplicably loosing coolant. never had white crud on my glow plugs but i never pull them lol, but when i did, and i did have a head gasket failure.
How is the oil look? sane with the coolant? we need more informaiotn
compression is spotty, you need to do a leak down test and find where your missing compression. a few drops of oil into the piston from the glow plug hole and compression clears up as normal or gets significantly better, you have blown rings, if air comes out of tail pipe = exhaust valve, intake manifold=intake valve, dip stick= rings, coolant tank= head gasket
 

steve6

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May 25, 2010
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Beaverton, ON
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2003 jetta tdi
The variance in compression indicates an issue regardless, car history? Run away at any point? What is the actual car and engine?
 

UhOh

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2000 & 2003 Golf GLS (2005 Mercedes E320 CDI)
Those numbers are pretty wonky. Of importance, however, is the relative numbers. Odd that #2 is 460. 460 vs. 360 is over/out of spec/range. 400 vs 360 is not. I'd look to run another compression test.

White smoke started when? What's the history of this engine?

Are you losing coolant?

Any coolant in the oil or oil in the coolant (seeing any bubbles in the coolant reservoir tank)?

What can you tell us of the injectors?
 

flee

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Joined
Sep 19, 2011
Location
Chatsworth, CA
TDI
2002 Jetta GLS wagon
I'm guessing this is the donor car for your 4-runner tdi swap project.
Since the engine will be pulled anyway, I'd go ahead and pull and freshen the head.
Be sure to check the piston protrusion, deck flatness and the head flatness, of course.
Look carefully for any sign of piston to valve contact; it will be visible on the piston top.
If there is anything wrong with the head I would send it to Franko6 or someone else
experienced with inspecting and rebuilding these heads.
Money spent now will save you plenty later.
If the head is ok, most head service shops can handle it if they do it by the book.
Finally, get a full timing belt kit from one of the trusted vendors here unless you
have verifiable documentation that it was bought recently and is still good.
Don't assume that anyone can properly install the timing belt. It should be done
by someone with the correct tools and experience. Don't skimp on this!
Again, money spent now will save you plenty later.
 

KBCB

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Oct 14, 2015
Location
CO
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This car is a recent purchase '03 Jetta TDi. My plan is to fix it up for the wifey so she has a car that gets better MPG than our Toyota pickup, for her 60mi commute. And introduce her to the better fuel source.:D

The guy I bought it from told me about the white smoke and power loss during acceleration on the highway. I can't confirm the power loss during acceleration, however it's definitely blowing white smoke. I have been hesitant to run it much not knowing exactly what's going on and not wanting to do further damage to the engine.

I don't see any coolant in the oil looking at the dip stick. Also I don't see any oil in the coolant. In the overflow reservoir there is some crud built up on the sides. Hard to say if it's related or a byproduct of not using distilled water. The coolant was low (the red light on the dash was blinking) So I did add some water last night. I didn't at any point see any bubbles in the coolant. However, I also didn't get the engine to operating temperature either. Ran it for maybe 5 minutes, again not wanting to cause any further damage.

I have a leak-down tester and was going to run that test but the kit I have (Harbor Freight) doesn't have the right adapter. Has anyone found a place to get the correct one?

Appreciate the thoughts!
 

flee

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Joined
Sep 19, 2011
Location
Chatsworth, CA
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2002 Jetta GLS wagon
Obviously the low coolant is a possible warning sign.
Has there been any mods done to this engine? If it still has the EGR cooler intact,
that could be the source of the coolant loss and white smoke.
A leaking EGR cooler can vent coolant into the exhaust and exhaust into the coolant.
 

UhOh

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2000 & 2003 Golf GLS (2005 Mercedes E320 CDI)
As it stands, however, those compression numbers are not good. I think that it might be more instructive to prove these as if they hold it's a head gasket or possibly worse/more substantial.

Make sure you don't have any oil pooled up in the IC. Possible that #1 got a bit of a hydrolock (though #2 and #3 are known to be the most common recipients of abuse from inhaling extra liquids).
 

muzy

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Aug 19, 2012
Location
Southern Alberta
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02 jetta TDI
How do you test a EGR cooler for leaks? Same way I would check a bull dozzer? Uninstall and fill with gasoline and watch the pipes.
Cheers
 

hey_allen

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Nov 25, 2006
Location
Altus, OK
TDI
2000 Jetta TDI
Another option would be to test it like a tire: uninstall, pressurize and submerge it, see if you have bubbles.

You could possibly unhook the coolant plumbing and do a leak down test, by applying a known pressure and seeing if it bled off, but that assumes that you can get a nearly perfect seal at the port you are pressurizing and the other capped coolant port.
 

oilhammer

Certified Volkswagen Nut & Vendor
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Dec 11, 2001
Location
outside St Louis, MO
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There are just too many to list....
Not sure why you'd think this is a head gasket issue, I wouldn't.

I would have the injectors tested, and while they are out, take the intake manifold off and confirm the intake ports are clean.

Compression readings can get a bit off if the intake ports are not super clean.

You could have a slightly bent rod, from some mishap in the engine's past, or you could just have a poor injector spray pattern causing some less-than-ideal piston ring sealing issues.

Do the easy stuff first, before tearing the engine apart. The ALH is a pretty tough engine, but I do see plenty of people finding ways to somehow mess them up.

If you DO find the intake ports are gunked up, clean them out best you can with a shop vac and a pick, then check the compression again while the intake manifold is OFF. Make sure nothing can be sucked into the engine (shop rag, tools, small animals, genitals, etc.) while cranking. At least that way you can rule out any air flow problems causing a low compression reading. If you cannot get air in, you cannot compress it.
 

Mongler98

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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.
Compression readings can get a bit off if the intake ports are not super clean.
how on earth would any debris in an intake port, effect a compression test?
yea i get it, if it was so clogged that not even enough air can get into the chamber or something but if that was the case, i dont think this car would be running
but compression has nothing to do with anything past the valves.

he has much to high compression in #2 and not so good in #1, leading me to believe that the #2 has water built up in it thus increasing compression in #2 and that the #1 has the bulk of the leak on the gasket.
Only a leak down test at 150 psi or as high as you can go will revile Exactly what is wrong with the engine, hopefully. If its turbo head lift head gasket failure, leak down might not be enough to catch it, a blown head gasket, it will.
 
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oilhammer

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outside St Louis, MO
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There are just too many to list....
how on earth would any debris in an intake port, effect a compression test?
yea i get it, if it was so clogged that not even enough air can get into the chamber or something but if that was the case, i dont think this car would be running
but compression has nothing to do with anything past the valves.
Physics. I've seen it. I've seen intakes so gunked up back in the time before ULSD that the engines quit running.

Only such muck time to pull air into the cylinder. If the port is 50% blocked with crud.... :p

This is why compression checks are supposed to be done with the throttle (where applicable) held wide open.
 

jokila

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Location
Houston, Texas
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2003 Jetta GLS, Manual
Physics. I've seen it. I've seen intakes so gunked up back in the time before ULSD that the engines quit running.
Only such muck time to pull air into the cylinder. If the port is 50% blocked with crud.... :p
This is why compression checks are supposed to be done with the throttle (where applicable) held wide open.

Except this isn't applicable on the TDI since it's drive-by-wire, eh?
 

vincej

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Calgary
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2014 Golf Wagon
Well there is white smoke, coolant was down, and compression is lower in one cylinder. That tells me it could be a head gasket. A dirty intake could prevent a valve from fully closing though.

I wouldn't run it long with out fixing it. I don't know if it could happen with a diesel engine but years ago I had a leaking head gasket on a Rover 2000 TC and it ate the aluminum out of the head to the point of rendering it useless. Lucky for me I bought a wreck in town for a hundred dollars that had the spare parts.
 

KBCB

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Location
CO
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Interesting idea about the EGR. I don't have the plumbing diagram in front of me, could it make sense that a gasket on that system is blown allowing coolant to enter the exhaust while also reducing forward pressure to the turbo causing a loss of power? I think an EGR delete is in order anyways.

Going forward assuming the above doesn't address what I'm seeing, step 1 I'll pull the intake. Based on what I saw with the donor ALH that is going in my 4Runner the amount of crap that gets built up inside the intake of these engines is unreal. EGR + diesel = beyond stupid

Step 2 (and I'll probably do this anyways) pull the intake and clean.

Step 3 Leak down test. Can anyone point me to a kit they used, or just an adapter that hooks onto a quick connect air fitting?

It'll be a few days before I get back at this. I'll be sure to report my findings. Thanks!
 

UhOh

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If you operate these engines correctly then EGR + diesel is pretty close to a non-issue.

I've cleaned two intakes (and the head on one) and I have zero doubts that I'll every have to clean them again: I won't have to! Tune with Dynamic EGR, proper driving, good oils etc. etc.. And should emissions checks rear back up here I should be good (I can always switch my tunes if needed).
 

jokila

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Houston, Texas
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2003 Jetta GLS, Manual
Interesting idea about the EGR. I don't have the plumbing diagram in front of me, could it make sense that a gasket on that system is blown allowing coolant to enter the exhaust while also reducing forward pressure to the turbo causing a loss of power? I think an EGR delete is in order anyways.

Going forward assuming the above doesn't address what I'm seeing, step 1 I'll pull the intake. Based on what I saw with the donor ALH that is going in my 4Runner the amount of crap that gets built up inside the intake of these engines is unreal. EGR + diesel = beyond stupid

Step 2 (and I'll probably do this anyways) pull the intake and clean.

Step 3 Leak down test. Can anyone point me to a kit they used, or just an adapter that hooks onto a quick connect air fitting?

It'll be a few days before I get back at this. I'll be sure to report my findings. Thanks!
If the coolant is leaking through the EGR system, that doesn't explain the low compression in the one cylinder. Did you perform the test a few times to average the readings per cylinder?
 

belome

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2002 Jetta GLS TDI 5-speed
Maybe the better question... is the Compression tester also Harbor Freight?

In theory, it "should" be off by the same amount on each cylinder... but how much can you really rely on it?
 

UhOh

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PNW
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2000 & 2003 Golf GLS (2005 Mercedes E320 CDI)
Maybe the better question... is the Compression tester also Harbor Freight?

In theory, it "should" be off by the same amount on each cylinder... but how much can you really rely on it?
I've never heard of one being inconsistent. Only problems have been that they report evenly high or low OR outright not working (usually a bad Schrader valve).

Bigger problem is with technique. Need to ensure battery is properly charged: if the charge drops significantly then subsequent cylinder will read lower due to this. Never thought (or read) about ensuring that the ASV is fully open, as Brian notes, but if he says this is something to check/watch out for then that's good enough for me: another point that lumps in with the need to ensure proper testing technique.
 

KBCB

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CO
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Yes the compression tester is HF. No I don't expect it to be 100% accurate, only consistent.

I only did one round with the compression tester. I will go ahead and run it a couple more times.

Testing procedure:

Verified battery was at ~12.5V with the ignition off.
Disconnected the IP
Pulled #1 GP, installed tester fitting, had the wife crank until pressure quit building. Replaced #1 GP.
Pulled #2 GP, installed tester fitting, had the wife crank until pressure quit building. Replaced #2 GP.
Pulled #3 GP, installed tester fitting, had the wife crank until pressure quit building. Replaced #3 GP.
Pulled #4 GP, installed tester fitting, had the wife crank until pressure quit building. Replaced #4 GP.

Since I started with the #1 cyl the battery voltage shouldn't be the cause of the low reading. And the two tested last were reading even. However, This was the first time I had used this tester so it is possible that it needed to cycle a few times before it will read consistently. Again I will rerun all cyl a couple times and see what they look like.

For those that are asking it's the white smoke and low coolant more than anything that leads me to believe that it's a headgasket. There may be other issues with the engine, that is showing up with the low compression, but by the time an engine is blowing white smoke it's screaming for attention.
 
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oilhammer

Certified Volkswagen Nut & Vendor
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outside St Louis, MO
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There are just too many to list....
While I have never seen an ALH EGR cooler fail, I suppose it is possible. Seen some BHW ones do that.

With ALL the glow plugs out, you can also pressure test the cooling system, and see if anything happens. I'd probably take the EGR valve loose to see if the cooler is indeed bad, you can possibly look down inside it and see pink.

There is a distinct difference between coolant smoke and diesel/oil smoke. One smells sweet, one does not. Coolant smoke looks like steam, diesel/oil smoke will have a bluish tinge to it.

Head gaskets rarely fail on the ALH.
 

jokila

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Location
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2003 Jetta GLS, Manual
Yes the compression tester is HF. No I don't expect it to be 100% accurate, only consistent.

I only did one round with the compression tester. I will go ahead and run it a couple more times.

Testing procedure:

Verified battery was at ~12.5V with the ignition off.
Disconnected the IP
Pulled #1 GP, installed tester fitting, had the wife crank until pressure quit building. Replaced #1 GP.
Pulled #2 GP, installed tester fitting, had the wife crank until pressure quit building. Replaced #2 GP.
Pulled #3 GP, installed tester fitting, had the wife crank until pressure quit building. Replaced #3 GP.
Pulled #4 GP, installed tester fitting, had the wife crank until pressure quit building. Replaced #4 GP.

Since I started with the #1 cyl the battery voltage shouldn't be the cause of the low reading. And the two tested last were reading even. However, This was the first time I had used this tester so it is possible that it needed to cycle a few times before it will read consistently. Again I will rerun all cyl a couple times and see what they look like.

For those that are asking it's the white smoke and low coolant more than anything that leads me to believe that it's a headgasket. There may be other issues with the engine, that is showing up with the low compression, but by the time an engine is blowing white smoke it's screaming for attention.
Look under the car for telltales of dried pink coolant. You could be losing coolant through weeping flanges. Is the white smoke showing even with the engine warmed up? Is it constant out the tailpipe?
 

need4speed

Veteran Member
Joined
May 4, 2004
I recently went through this exercise: (ended up being a blown head gasket - but there are different blowout scenarios that behave differently - and I did not have a compression-tester).

My ALH never had white smoke coming out of the exhaust. It actually pretty much ran fine, and for several months, would take 10-15 mile drives on a daily basis, but if you drove it on the freeway, it would overheat. This was apparently triggered by a low-coolant episode caused by a leak in the radiator return hose. (or, possibly, after the leak was repaired, the car was driven with too-dilute coolant, because the lost coolant was replaced with distilled water; which makes it boil at a lower temperature, and also degrades the viton in the MLS head gasket).

Coolant leaks can be traced (even EGR leaks) with a fluorescent tracer dye. If it is ingested in the EGR valve, you should see trace in the intake downstream from the EGR with a UV light. If there are leaks anywhere else: fluorescent tracer dye will reveal it. (unless it's coming in through the water-jacket and head-gasket; I don't think there's a practical way to look in there if there's even trace visible). Though, when I took my EGR cooler off, I looked at it, and couldn't really imagine how that could develop a leak, it's a pretty sturdy and solid piece of hardware. (and very, expensive to replace). I used my mighty-vac, and rigged a sprinkler fitting, and just plugged the other end with my finger; and it held vacuum, so I figured that meant it was airtight.

If you see bubbles in your coolant reservoir coming from the coolant return hose, or soot, or if the coolant system is pressurized after sitting overnight, or if the pressure relief valve in the expansion tank getting tripped and level going up, any of those mean that you've got a blown head gasket. If your expansion tank is overflowing, then you'll see coolant on the ground under the car behind the front-right tire just generally dripping from the frame. (for me, it was actually kind of hard to figure out where this was coming from until I got the dye - but in retrospect, looking at the expansion tank being filled; it was obvious).

White-smoke has already been covered; so here's the thing about whether the white smoke is fuel, or coolant:
If it is fuel, this could be the result of a blocked intake, and you can rule out two pretty common causes.
That could either be build-up of soot in the intake, (which has also been covered), OR, a broken EGR cut-off butterfly; the little plastic vacuum actuator on the back of the EGR is pretty fragile, and commonly breaks, and if the arm is broken, then the butterfly valve can kind of flop loose. You'd see that immediately if you took off the intake hose. If it's closed, you'd get really crappy power, and white smoke that smells terrible. There is a lever on the back of the EGR assembly that you can control with your finger (if that plastic arm is broken, or disconnected).

So that's easy to rule-out. I thought I'd mention it. And unburnt diesel is really stinky.
 
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KBCB

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CO
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well... poop!

I needed to move the car out of the garage yesterday to finish up another project. When I started it I didn't notice any white smoke. So I decided that I would go ahead and see if I could re-create the initial problems as described to me.

I gingerly went down the driveway and got onto the main road. Things seemed to be going ok. Then I gave it maybe 1/2 throttle then noticed lots of smoke coming out the back. Started backing off the throttle. Couple seconds later the RPM's started picking up. CRAP! Shut off the ignition and put the clutch in and started making my way towards the shoulder. After maybe 10-15 seconds with the engine racing BANG! Things started coming apart, and the engine sounded like a bunch of bolts in a coffee can. Got to the shoulder, got out and saw bits and pieces all along the road with a nice oil streak.

So drug it back home, got it back in the garage. The block is cracked in at least 2 spots that I could see. Near the bellhousing, and near where the dipstick enters. I'll post up some carnage pictures later this week.

So looks like I'm in need of a new ALH block! Thanks again for all the thoughts and suggestions!
 
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