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914World.com _ 914World Garage _ I think I have a head leak

Posted by: Headrage Nov 26 2005, 07:08 PM

My car has the faint dreadful puffing sound coming from the right side of the motor. I stuck my hand up around the exhaust and could feel air blowing in a steady stream. It wasn't hot air or coming out in a quick puff, puff, puff like I would think escaping exhaust gasses would be.

When there is a load on the motor when accelerating the exhaust note becomes very deep and loud. Like the sound of a Harley with open pipes. Once up to speed it gets really quite.

Am I doomed???

Posted by: J P Stein Nov 26 2005, 07:21 PM

I had this happen at an AX once. The plug for the air injection
port fell out. I laid under the car while the engine was running to find it.....Not too bright but effective

Posted by: Porsche Rescue Nov 26 2005, 07:27 PM

Is it a 2.7? If so, JP may have diagnosed it. Could also be an ordinary exhuast leak at the head. If you have headers you should be able to look up there and see black where the leak is. A lot harder to see if you have heat exchangers.
Noise under load, quieter on slack throttle, sounds like exhaust, not head.

Posted by: Headrage Nov 26 2005, 07:28 PM

What's the best way to validate my worst fear???

Posted by: brp914 Nov 26 2005, 07:37 PM

hows about doing a compression check. Also, might want to take off the valve covers and make sure those head studs are snug. Especially the lowers. Not a real happy place on 2.7's. good luck

Posted by: r_towle Nov 26 2005, 08:13 PM

a compresion test will give you a rough idea...a leak down test will give you much more detail...

Rich

Posted by: Headrage Nov 27 2005, 04:54 PM

Put the car up on jack stands and crawled around for awhile hoping to find and obvious source of an exhaust leak but couldn't see anything based on my very limited experience. I did notice that one of the air injection ports was plugged with what looks like a 6mm bolt with the head sheared off.

Attached image(s)

Posted by: Headrage Nov 27 2005, 04:56 PM

I know the picture sucks. I'll try and get better ones when I get the car on a lift. I also noticed that on 2 of the exhaust studs had a bushing/spacer looking thing under the nut. Any clue?

Posted by: echocanyons Nov 27 2005, 05:12 PM

Looks like the exhaust studs are for the thick manifolds with a spacer to take up the slack.

Posted by: Headrage Nov 27 2005, 05:13 PM

QUOTE (echocanyons @ Nov 27 2005, 03:12 PM)
Looks like the exhaust studs are for the thick manifolds with a spacer to take up the slack.

Only on 2 of them?

Posted by: echocanyons Nov 27 2005, 05:17 PM

maybe teh others were repladced with the proper ones

Posted by: Headrage Nov 27 2005, 06:08 PM

Okay, started the car and climbed under it and could definitely hear a leak but couldn't see or feel a thing.

BTW, it gets warm quick under there...

Posted by: J P Stein Nov 27 2005, 07:14 PM

In the pic:

A spacer on a stud like that has to be thick....diameterwise.
Tubing will deform quickly and allow the nut to loosen...gasket starts leakin'....yada. Note to cobblers: you're better off with a stack of washers.

To the upper right of your lower box....got it? There's a glob of black gooey lookin shittage. If the head starts leakin, that's where it will show and in that form.....

I would put it in the air. Pull the headers. Replace the studs with the proper ones (this can be a real stinker as the old ones like to break.). The old gaskets will show signs of leakage if that is the problem......IF they seem good.
Drain the oil. Pop off the lower cam covers. Check the head bolts for tightness (if none fall out in your lap.)

Warm?. Indeed. It's a quicky, in and out.....

Good luck.