[Nickelfire]

Okay, daughter calls me with dead car, I figure out it is the fuel pump, replace it, sure enough it was. However, upon starting it back up I get the weirdest ticking (light metallic, sounds like valvetrain, not rod knock) Pull the plugs, 3 of 4 wires disintegrate on me, the plugs look wrong and number 4 is not firing....it's wet when I pull it (Plugs were for the T bird Super coupe) replaced all that, but still the annoying light ticking. I did a compression check and had 105, 25, 105, 0. The coil is good, as is the ECU, I assume the crank trigger is also good or it wouldn't run or it would give me a code (no codes so far either).

My question is, is this related to this valve seat "dropping" I have been coming across on the threads? If so, is the head savable? The rest of the car is fine with about 110 K on it and it seems to be okay everywhere else. I have the ability to do the R&R myself, and we have some great machine shops in town, or should I just go to a rebuilt head from a shop?

Thanks for the Forum btw, you all helped me isolate her problem.

 

[Nickelfire]

Oh, and as a secondary note, she was running around with about a quart low on coolant. If I replace the head, do the head bolts need to be replaced along with the timing belt? And what are other things that should get my attention with the head rebuild?

 

[BC_ZX3]

Zero compression in any cylinder is not good, particularly when it's only in one. (Sometimes two zeroes beside each other can be a bad head gasket.) Cylinder #4 is the one that's usually affected by seat drop, IIRC.

With two dud cylinders, check the timing belt first to make sure it hasn't shed teeth and that the timing hasn't jumped.

If the engine has dropped a valve seat or seats, the head will definitely need rebuilding and likely the piston top(s) will be badly mangled. Some have had bent rods as a result also. The cylinder bore may also be scarred.

 

[Nickelfire]

Thanks, old hat for some of you I am sure. I never got to check this car out for her, why do they insist on doing everything themselves.... Update: of course it couldn't be as easy as the timing or the belt. I have access to 3 cars that were running, but wrecked with heads intact, new question is 100 K about the time frame you see this happen on the head? And would a 2003 ZX3 (80k) drop in, besides the ECU and associated peripherals?