Leaky headgasket or just paranoia?

Heads, valves, pistons, rods, crankshaft, etc...

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suba
First Gear
Posts: 157
Joined: Sun Jun 14, 2009 8:27 pm
Location: Moscow, ID

Leaky headgasket or just paranoia?

Post by suba »

The Car: 90 Legacy L 5mt, 200K, N/A

Recently my car has been running a bit rougher at idle so I did a bit of a tuneup: plugs, cleaned maf (i have a K&N), new O2 sensor (walker), reset ecu, fresh oil and oem filter.

The idle improved quite a bit and the engine runs smoother overall...but...

Yesterday while driving behind my car I noticed when the driver shifted or stepped on it up a hill a tiny puff of whitish smoke would come out the tailpipe. I first noticed it about mile after we started down the road, so could have been some condensation. Also when headed up a long climb (about 5 miles at 6-7% grade) in fourth at about 70 (~3500 rpm) the car just simply won't push any farther. I don't expect a whole lot of power out of this engine, but it definitely used to be able to pull the hill a bit better which makes me wonder.

Also though the idle is significantly better it is not nearly as smooth as it used to be. The car isn't using any coolant that I can tell, oil looks fine (no milk). I don't have access to a compression tester at the moment and a few other projects are in the way but I'm going to try and do that sometime soon. The real question is it possible that I have a tiny headgasket leak or am I just paranoid? Thanks for the input
90 Legacy L AWD 5mt
Formerly of the USMB but moved from an RX to a Legacy
suba
First Gear
Posts: 157
Joined: Sun Jun 14, 2009 8:27 pm
Location: Moscow, ID

Post by suba »

Oh, also I guess I should mention the reason I first started to wonder. A while back I noticed at startup and under initial acceleration I could hear water rushing in the heater core. I haven't noticed it a lot, but occasionally I turn off the stereo to see if I can hear anything. Of course at this point I may be just making up things in my head.
90 Legacy L AWD 5mt
Formerly of the USMB but moved from an RX to a Legacy
log1call
Second Gear
Posts: 390
Joined: Mon Jan 22, 2007 5:22 am

Post by log1call »

Compression tests are not really a good test for head-gaskets. By the time the gasket is leaking enough to effect the compression the motor will have over-heated many times over.

The best test for blown head-gaskets is a hydro-carbon sniffer that tests the radiator water for signs of hydro-carbons. The testers are called tee-kay, (well that's a well known one make anyway). I'd recommend you go to a service centre and ask them to do one, it may be a free test if they think they are getting a job out of it.

It only takes a few minutes to do. They just drain a little water so the sniffer doesn't get water into it, then they run the motor and pump air from in the top of the radiator through a liquid which changes colour if there are hydro-carbons getting in there.

The tee-kay test will find even tiny head-gasket leaks and is very dependable.
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