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blown head gasket?

Did a compression test on my 98 Toyota Camry, not expecting what I found out.

Cylinder 1: 110 Cylinder 2: 50 Cylinder 3: 180 Cylinder 4: 180

I retested a few times on #1 and #2 to make sure I had the hose screwed in tight and all the way.

Now I am thinking of doing a leak down test but is it really necessary to get an air compressor for the air source? What's the minimum psi that would be able to perform such a test? Should leakdown test be performed with cylinder at TDC or BDC (I've seen both suggested, BDC so that engine doesn't turn over)?

I think the important thing is the variation amongst the cylinders, not the actual readings so much because with a 2 foot extension air hose connected to the guage, the readings all drop by alot. My top readings go to about 80 psi. Other than that, I'm not sure what could be causing the low compression on #1 and #2.

I haven't ever seen coolant in the oil or oil in the coolant, but I have noticed a small coolant loss that must be replaced about once every week and a half or so, about 20 ounces or so into the expansion tank.

The car seems to run fine, although I think it doesn't have quite the acceleration that it should - my only indication that the low compression really exists and not just on a gauge but again, is this a problem that will get worse and worse until fixed?

Thanks.

Reply to
August
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The compression readings seem to clearly indicate a blown head gasket, and a leakdown test most likely will only confirm it. As such these things do not get better with age. Eventually the leak will get worse and you will get contamination, and this will result in rapid wear on the bottom half of the engine. Letting it go will also result in erosion of the mating surfaces of the cylinder head and block, which could lead to needing to additional machining or replacement. The coolant is probably venting into the combustion chamber, where it is burned. It is a fairly expensive problem now, but if you wait it will become a hugely expensive problem later.

Reply to
Bruce Nolte N3LSY

You cannot say for sure based on the compression readings that the head gasket is blown. Since readings appear to be low on 2 adjacent cylindes, that would be a likely problem, but burnt valves, stuck/broken rings, cracked heads can also cause low compression. If the car doesn't smoke or lose oil, the rings are probably OK, but if you put a teaspoon of oil in the sparkplug hole and retest, the numbers will improve if the rings are the problem. The leakdown test may also help pinpoint the cause.

Reply to
bobby

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