drop in gas mileage and gauge problems

Anybody think a compression test might be in order, to see if the valves are seating properly, or what are the chances the timing is off a tick, since the head gasket(s) were just done? I'm really unsure the possibility of running the motor with the timing off a tick though, as it's interference. I was told that Subaru's aluminum heads needed to be checked extremely well for flatness when doing gaskets, and sometimes baked and straightened from warpage before flattening, or the problem has a high likelyhood of repeating itself, and it may even be necessary to do valve guides?

Don't yell at me guys, just suggesting. I would think a compression test far better than burning a valve, if anybody even thinks it could be that, or maybe it's just running rich?

~Brian

If the timing was one tick off "Retarded" it would run smooth,make poor fuel mileage and run hot..... I suspect your are correct.A compression check WILL NOT show this problem.A "Leakdown" test will show valve condition only. I would suspect the camshaft is one tooth retarded.

Try holding a strip of paper against the tailpipe. If it tries to 'suck in' , could indicate improper valve timing. I dunno if a bad Engine Temp Sensor could cause this poor mileage, but it may have coincidentally gone bad.

Carl

is the inaccuracy of the gas gauge an indication of the problem?

I would rely on the fill up system to estimate fuel consumption.

The problem could have many probable causes, among them, the coolant temp sensor, leaky fuel injector, low tire pressure, etc. etc.

Can you have your car scanned to see if there are any codes that have not set the check engine light yet?

Good luck!

snipped-for-privacy@gmail.com wrote:

i figured it can only be related to fuel since i smell gasoline, my gauge is screwed up (read anywhere between empty and full today after filling up).

my friend looked in my Haynes manual suggested maybe a fuel pump problem?

If you smell it out the tailpipe I can only dream up about 4 ways that could happen. The Engine (not coolant) Temp Sensor is a known issue. Have it checked. I believe there is a fuel pressure 'regulator' at the end of the fuel rail, maybe its stuck and fuel pressure is too high? (anyone?). I suppose an injector could be stuck or damaged somehow? maybe compare spark plugs and look for a distinct difference in one to indicate the cyl. with the bad injector - or have someone test them. Maybe some kinda vacuum or other fresh air leak is confusing the system and the ECU is trying to compensate with more fuel?

I dunno - just some thoughts

Carl