Head Gasket

[turboslug]

My engine has begun to idle ruff, and from behind the engine I hear a psst noise every time it studders. Could this be a blown head gasket, and how hard, and how much will it cost to fix?

 

[turboslug]

Sorry if it vauge. I don't really know what a blown head gasket sounds like. The problem started right after I got off the highway (thats when I noticed it). I had just got done playing "dodge the semis" going between 90-120. I did notice that durring one lane switch, I mashed and passed, and when I mashed I noticed a slight pop, I could feel it in the steerinf wheel. Then after I got off the highway I went to BK, sitting in line I noticed my C/E light was on and my car was studdering. It would still rev up, it actually runs better in higher RPMs. Boost is slow to rise. And a pssst, air leak noise comes from behind the engine at irregullar intervals. So air is leaking somewhere. I haven't noticed any oil anywhere. The only other thing I can thing of is a vacume line on the manifold.

 

[Kevin90GSX]

Im not exactly sure if its your head gasket. Maybe the psst your hearing is a boost leak of some sort.

Dont call blown gasket yet. Check your oil and see if its thick.... you could also drain a little of your coolant and see if there is any oil mixed in.


EDIT: Read your second post. I doubt its your headgasket. You could have popped a hose somewhere. That would definitely throw a CE. Check all your vacumm lines and if you have a friend with a logger have them run a log and see what the CE code your getting is.

 

[GTM]

Originally posted by Kevin90GSX
Im not exactly sure if its your head gasket. Maybe the psst your hearing is a boost leak of some sort.

Dont call blown gasket yet.
...

I'm in agreement with the headgasked, very rarely will they make a sound when they blow and then it will be a puff puff puff etc. That is if they blow to the outside, more likely between 2 cylinders or into a water passage and you will hear nothing.

More likely the air inlet hose has blown off at the turbo or the fitting just upstream. Had to double clamp that on my son's car after we installed a good used turbo. Give a bit of a tug on them for they will fall back as if they were attached and be overlooked.

If that's not it then look for other vacuum hoses off or cracked on the intake manifold. They will cause a most noticable hiss and easy to find. This will cause a rough idle and major hesitancy when trying to accelerate for the fuel mix is incorrect.

Watch the hard on, off, on the throttle situations for the turbo is wound out tight and the safty mechanisms can't respond fast enough to the extra boost thus can blow hoses. Even the boost gauge may not respond fast enough to see it happen before the hose popps off.

Cheers,
GTM

 

[turboslug]

I checked all the vacume lines, and changed the spark plug wires. To be noted, I do have a lot of blue smoke out of the tail pipe. Now I have earlier (when I got the car, June) thought that the headgasket might already be internally blown and this would be the because of the smoke. Now it seems thought that it is blowing even more smoke. So maybe I finishished it off. Also the psst noise sounds like it leaking air back into the intake. Throttle response is good. when it revs up fast it doesnt studder, but if I hold it at lets say 3k it will studder as if it were idleing. The psst noise only comes when it studders, like it misfires. But spark is good. I am also considering changing the injectors and the fuel filter. Since I can do that for free.

 

[Kevin90GSX]

Originally posted by turboslug
I checked all the vacume lines, and changed the spark plug wires. To be noted, I do have a lot of blue smoke out of the tail pipe. Now I have earlier (when I got the car, June) thought that the headgasket might already be internally blown and this would be the because of the smoke. Now it seems thought that it is blowing even more smoke. So maybe I finishished it off. Also the psst noise sounds like it leaking air back into the intake. Throttle response is good. when it revs up fast it doesnt studder, but if I hold it at lets say 3k it will studder as if it were idleing. The psst noise only comes when it studders, like it misfires. But spark is good. I am also considering changing the injectors and the fuel filter. Since I can do that for free.

good call. Do the fuel filter and replace your injectors and/or have the current ones cleaned.

I still dont think its your head gasket. Check the fluids for oil being thick and coolant having oil.

Can you build boost? Maybe you blew your turbo or something. A bad seal will caused smoke.

 

[turboslug]

Yeah. I think I'm going to do that. If that doesn't work I can get an engine for 200 bucks from my roommate. Its wierd thought the C/E light comes on, then it goes away, and just shows up again on certain days. I've been reading that you can make a diagnostics tool with an LED. Does that really work?

--I can build boost, but not as fast as usual
--Oil level is fine
--Coolant looks good.
--New Spark wires
--Checked Vacume lines



Has idles rough before, but when I gave it a little gas it stopped. This is what I'm using to validate changing injectors and filter.

 

[Kevin90GSX]

well time to do the injectors and fuel filter. Always do the small things first then go crazy with replacing the engine.

 

[sfrye]

If you are getting blue smoke, it is definately an oil leak. Have you checked compression? How about a leak-down test? Try revving the car in neutral to about 3K and see what happens when you hold it there for about 10 seconds. If you get more smoke and more misfiring, it could be your valve guides leaking oil down into the cylinders. Have you checked the spark plugs? If one or more of them looks like it has black stuff on it, then it is likely an oil leak. You can also check if it is one of the exhaust valve guides by removing the exhaust manifold and seeing if you have a buildup of burnt oil coming out of one of the exhaust ports.

Sean

 

[lowavenger96]

It is probly one of 3 things ..


1.. Boost leak
2.. blown intake gasket..
3.. Ablown injector seal

I would bet on the intake gasket....

 

[GTM]

Originally posted by turboslug
...
If that doesn't work I can get an engine for 200 bucks from my roommate. Its wierd thought the C/E light comes on, then it goes away, and just shows up again on certain days. I've been reading that you can make a diagnostics tool with an LED. Does that really work?

--I can build boost, but not as fast as usual
...
Has idles rough before, but when I gave it a little gas it stopped. This is what I'm using to validate changing injectors and filter.

Geepers, you all of a sudden have more info which introduces other possibilities.

A blown headgasket does not cause a lot of oil smoke. Burning up an engine after a blown headgasket will cause smoke. Most often a headgasket will leak into a cooling passage and you will start loosing coolant along with the engine overheating.

You didn't mention if you checked the inlet hoses before the turbo... that will cause a slow boost. I don't see the relationship between this sudden occurance and fuel injectors and some of the other things mentioned.

If the coolant is ok and it's oil smoke then it's rings, valve guide seals or turbo seals. However, this may have nothing to do with the other problems you are having. A rich running engine can dilute the oil at the rings and get wiped up to the combustion area where it will burn with blue smoke.

We can only make mention of these things, you have to look for the obvious and then check for the overall engine condition.

Have you checked the turbo to make sure it's spinning free and there is no shaft play. Maybe it's not a hiss at all but the turbines hitting the turbo body. Leaking turbo seals will cause a lot of oil smoke. Compression check is in order allso if it's not something obvious. There is a difference between oil smoke and antifreeze smoke, besides it has a different smell if you can make it happen while parked.

Yes it's possible to use the led to pull codes.

If that's a half decent 6 bolt TSI engine for $200 you should grab it for winter is coming and a rebuild in your spare time is well worth the effort. Since you won't be in a hurry you can shop for the best prices for parts as they come up and end up with one sweet engine.

Cheers,
GTM

 

[turboslug]

Well the problem got worse on my way back from work the other day. I pulled the plug wires one at a time and let them spark to the valve cover. It looked as though my coil was going bad, so I ordered one, should be in today. Hopefully this will fix it.

 

[GTM]

Originally posted by turboslug
Well the problem got worse on my way back from work the other day. I pulled the plug wires one at a time and let them spark to the valve cover. It looked as though my coil was going bad, so I ordered one, should be in today. Hopefully this will fix it.

There is another possibility which wasn't mentioned... spark plug wires. If you know which cylinder is misbehaving you can sometimes switch the wire and see if the problem then moves to that cylinder. I have had plug wires which would work fine one day and not the next. This is highly unusual and it had me stumped for several weeks as I tried everything else. It wasn't related to morning or evening, cold or hot engine, just would happen.

Cheers,
GTM