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Questions and Answers

Toyota Camry, Very Poor Compression

Q. Vincent, I have a 1992 Toyota Camry, 2.2 liter 4 cylinder, automatic transmission and 150,000 miles that was working great until one morning a couple of weeks ago when it suddenly wouldn't start or even sputter. The engine would crank fine, so I checked and found that I have good spark and that fuel is moving through the lines.

Toyota Camry, Very Poor Compression

A squirt of starter fluid into the intake manifold didn't do anything. When I removed the distributor cap, the rotor appeared to be slightly past the #1 spark plug wire with the crankshaft pulley set at 10° BTDC, so I thought the problem might be a bad timing belt. However, the timing belt had no visible defects and the crankshaft pulley and camshaft pulley were exactly synchronized.

A couple of compression tests with different gauges showed low pressure in all 4 cylinders, 40 to 50 psi, and when I set each of the pistons in turn to TDC of the compression stroke and blew compressed air into the spark plug holes I could feel small amounts of air leaking out of the other spark plug holes, exhaust pipe and in the vicinity of the fuel delivery pipes. This doesn't seem right.

The problem must be in the cylinder head, but what could go wrong literally overnight? Could the intake and exhaust camshafts be out of sync and what could cause that?

Thanks,
Chris

A.

When you pump a cylinder with compressed air and you get air out of one or more of the other cylinders, you have either a blown head gasket or a cracked cylinder head.

When you pump a cylinder with compressed air and you get air out of either the exhaust pipe or the intake, you have an exhaust or intake valve not seating.

You can do a cylinder leak down test with a hose that screws into the spark plug hole and connect a compressed air line to. This will force the piston to the BDC position. Then if you get air out of the other cylinders you will know for sure it's a blown head gasket or a cracked cylinder head.

If you get it out the intake and/or exhaust, you know you have a valve problem.

With the piston at TDC you might have a valve still slightly open giving you a false valve problem indication. I believe it is far more likely you have a blown head gasket or cracked head. Possibly a cracked head since it happened overnight.

Additional Information provided courtesy of AllDATA

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