I have a 92 Protege that I have driven for a year with no problems till just recently.
I was getting on the freeway at a moderate speed and I had an immediate loss of power.
I did some trobleshooting and found # 3 cylinder to have 55 lbs of compression.
I pulled the valve cover and positioned the cams so that both intake and exhaust on #3 cylinder were closed, and supplied air to the cylinder. I found air to be escaping out of #2 cylinder.

Could someone with experience on these heads please give me some advice.
Thanks in advance!
Bob P.

 

How did the compression in the rest of the cylinders look? If you had #3 at TDC compression stroke with both valves closed then #2 would have been at TDC exhaust stroke. Exhaust valve does not close untill 14' ATDC so if you had a burnt exhaust valve at #3 you would get air coming out of #2 cylinder plug hole. Do you also have air coming out the tailpipe? Is harder to detect there but a lit cig stuck into the tailpipe will point to air escaping much better than trying to feel with your hand. If air is coming out the tailpipe then would be considering a burnt valve and if not then a possible headgasket leak between the adjacent cylinders. Burnt valve not very common problem on that engine but then neither are headgaskets.

 

Thanks for the reply Babyhuey.
Your knowledge of this engine is far greater than mine. I did not check the tailpipe for air when I did the test.
The other three cylinders are between 155 and 170. I did add oil to #3 cylinder and it did not improve the compression. I feel confident that it is not a ring problem.
I need to pull the head and see what the problem is.
The way it lost power it is just hard for me to think that it is a burnt valve.
Thanks again for the reply, and I will keep you updated on the outcome.
Bob

 

I would venture a guess at the head gasket also. I have seen many 4 cyl engines do this. If it was a valve problem you would not hear air escaping from the adjacent cyl. Worst case scenario would be a cracked head.

 

I am hoping it is the gasket. If it is the head I will have to think about how much money I will have to sink in it to fix it.
I always have enjoyed driving it. With the fuel prices the way they are now especially.

 

I as well hope it is the headgasket but am fairly skeptical given the good compression readings that you report from other cylinders. If a head gasket was ruptured bewteen the #2 and #3 cylinders then #2 should have also given a low compression reading similar to #3.
You are the boss on the way the engine lost power and a burnt valve should show up in a more gradual way but not many other things that will kill compression in only the one cylinder. If compression was down in all then a jumped timing belt might come to mind but with compression good in all other cylinders then the problem seems to be isolated down to a single fault area.

 

I thank everyone for the helpful replies. I am pulling the head tonight.
Bob

 

Pulled the head and found one of the exhaust valves on #3 to have a chunk missing out of it. Looks to me like a foreign object damaged it. Replacing the valve,seals, and lapping all them in.
I would guess that when I pressurized #3 The intake valves on #2 were not fully closed. I do not see any problems with the gasket.
Bob