Do I have a blown head gasket, or is something else wrong? Here is what's happening:

1. On cold startups, the car idles rough. Seems to only want to idle at around 600-700rpm. If I depress the throttle slightly, it runs smoothly at 900rpm. When warmed up, idle is smooth at 900rpm. I've already reset the idle speed using the instructions at Clark's, but no change.

2. I've got a Reliaboost-II, but I seem to be unable to set the boost beyond 11-12psi. It just doesn't go any higher.

3. Manifold vacuum is not good. 12inHg when cold, 16inHg when warm.

4. Losing coolant from reservoir. Disappears, can't see it on the ground. No leaks that I can see. Yesterday, after less than 10miles of driving, the coolant level changed from the 'max' line to halfway between 'max' and 'min' (level checked when cold). Nothing went out the overflow, as the overflow tube is completely dry.

5. Looking at the oil filler tube today, there was some amount of chocolate milkshake there. (see picture)

6. Looked at spark plugs; on #3, one side of the electrode seemed to be a tiny bit shinier than the other.


So from this I want to say a leaking HG is likely.

BUT:

1. No white smoke on startup or when under boost that I can see.

2. Oil on dipstick looks fine.

3. Drained a quart of oil today: looks fine, maybe some tiny bubbles in it, but didn't look unusual.

4. No oil in the coolant at all.

5. Car runs fine overall.


Is there a surefire way to tell whether this is a leaking headgasket, an oil cooler seal problem, or something completely different?

Thanks!!

Gary.

 

Do a compression test.

When my HG was toasted (a lot worse than yours) I was going through bottles and bottles of coolant...and my #2 spark plug was drenched in coolant.

I had the same idle problems that you do.

When I pulled the head I found my #2 cylinder filled with coolant...

Anyway, I say headgasket based on your symptoms.

 

You may have more than one problem, and may not be related.

- Rough Cold Idle.
- Missing coolant. Perform a cooling system pressure test, if you have leaks, they will become visible.
- Check all of your plugs and do a leakdown/compression checks if you do not find a leak in prior test.

There is a chemical test of the coolant which determines a blown headgasket.

Based on your description, I'm thinking the headgasket is fine..

 

Same as Adrial. Let it idle from cold for few seeconds, then pull the plugs. One will probably be extra clean. It's just starting to go, but get it fixed.

 

You may want to run a leak down test. Are you sure you are losing coolant, and that the level is not fluctuating as air pockets move around? Does it just keep getting lower no mater what? Does engine temp run hot and/or over heat if you drive with a heavy load (up a hill or over 80 mph for a while), but stay at normal temp if you just putt around? That tends to be a tell-tale sign that the head is leaking. Have you tried using coolant tracer and a blacklight to see if maybe coolant is steaming off from a tiny leak somewhere? Put your hand in front of the exhaust at the tale pipe and see if your hand gets wet -- after the car is fully warmed up. That is another tell-tale sign. If there is no mixing, and no coolant leak, yet you are losing coolant quickly, I'd also think the HG is suspect.

 

Adrial, last time I had done a compression test (~ 4 months and <100 miles ago), I had 145psi on #1 and #2; and 135psi on #3 and #4. However, a bit later the same day I rechecked compression on #3 and #4, and that time I got 140psi on both... it seems to me I can't get reproducible compression check results??

Thanks,

Gary.

 

fast951, so what could cause that milkshake in my oil filler tube, if it's not a leaking headgasket?

Do you know any details about the chemical test for leaking headgasket? Where can I get that done, or is it something I can do myself?

Thanks,

Gary.

 

Yeah... I may have a problem here... I just replaced the plugs about a month ago So they are all pretty nice and clean...

Gary.

 

Tom,

I just bled my cooling system very thoroughly a couple of days ago. I am getting good heat, even at idle once it's warmed up. This seems to indicate that I don't have very large air pockets in the system, I think.

My car used to run hot in stop-and-go traffic before, and a couple of times it puked coolant out the overflow after being shutdown. However, I have recently replaced the coolant expansion tank, and bled the system, and since then the car has been running cool and has not acted up at all. Coolant temps are below the middle gauge position; when idling for more than a minute or so, the temp goes up a little, but once the fans come on, it cools down again.

I haven't used coolant tracer, can I get that at NAPA or Kragen?

I've done the hand over exhaust pipe test numerous times; when the engine is cold, I get some water drops on my hand, but that could just be condensation. When warmed up, I can't see any water sprayed on my hand.

The whole thing really puzzles me! That coolant has to go somewhere, so where is it??

Thanks,

Gary.

 

The rough cold idle symptoms are classic.

You've probably got a small hg hole between a coolant passge and the cylinder, that isn't big enough to affect compression much. When you shut it down hot, the cooling system is still pressurized, and coolant leaks into the cylinder and collects. That plug won't fire until all the coolant is pumped into the exhaust.

Been there. Saw the bill.

The boost problem is probably something else, maybe a slit in a hose or connector.

 

Thanks all for your suggestions! Peckster's explanation sounds very logical to me. But I couldn't find any spark plugs that looked as if they were covered in coolant. And today I did a complete oil and filter change, and looked very closely at the oil: it looks just fine.

How much coolant do you think could get into the oil without showing up as discoloration, sludge, or milkshake? My guess is that at the very least over the last couple of weeks I have lost 2qt of coolant. If all of that mixed with the 7qt or so of oil, shouldn't that be very visible in the oil?

I think my action plan now is to have a shop do a cooling system pressure check and go from there. Any other ideas, anyone?

Thanks again!

Gary.

 

You've probably burned some of it. Just because you haven't seen it burn doesn't mean it hasn't burned.

I went through probably a gallon of coolant, and it wasn't visible in the oil when I drained it. I assumed that most of it had been burned.

I did have milkshake on the oil filler/cap, similar to yours.

 

napa will have both a 'block tester' that will test your coolant for exhaust gasses...and a cooling system pressure tester. try em both. then you'll know for sure, but it sounds like a HG goin - just liike mine did.

 

Update: I drove the car a little more over the weekend, and now the coolant level seems to have stabilized. It doesn't seem to have dropped over the last 20miles or so. Maybe, just maybe, I am lucky...

Next I think I'll invest in this nice-looking leakdown tester from harbor freight. Looks good for the price: http://www.harborfreight.com/cpi/cta...temnumber=4317

Gary.

 

i'd check compression / leakdown (do a wet test w/ the compression after the initial one). my guess is your boost problem, if not something simple like a hose, could be rings. your hg MIGHT be an issue from what you've said, but they fact that it "stabilized" is unlikely were it on its way out i'd think.