red1983

iTrader: (1)

Hi Everyone!

I recently moved to Alaska, after selling my '83 first gen, and I bought a cheap '90 Pickup. It has the 22-RE. This poor truck had been seriously abused by the previous owners, but, seemed to run fine. In my opinion had plenty of power and sounded good (minus not having a proper exhaust). But, I think this poor little engine has developed something bad.

I was driving home, up a street with a pretty decent hill, and suddenly the truck looses a ton of power, and the engine sound changes dramatically, It becomes rough and swoosh-y, almost ticky, sounding. I limp it home with the truck maxing out at 35 mph and backfiring constantly. I have discovered a few interesting things: 1. the farthest back cylinder is the issue. With the spark plug wire unpluged or the spark plug removed, the truck runs pretty good (minus only having 3 cylinders). 2. I installed a new spark plug because that cylinder's plug was in bad condition, lots of ash and, what looked like physical damage to the first treads and hook on the plug. I ran the truck for 10- 15 minutes with the new plug, removed it, and it also had the same damage.

I am not quite sure what to think, other than maybe I have two issues? I don't understand why in the middle of a drive home the piston would hit the plug out of the blue. There is a new sound in the engine, that I can only describe as a swishing/ swooshing sound, not at all metallic or rotational, even with that 4th cylinder not firing (wire removed) and I believe I heard it even with the plug entirely removed.
I am confused, and I kinda need this truck!

Any suggestions are much appreciated.

4wd4fun

if a piston hit the plug it prob hit a valve too and that could explain your swhoosh like noises. sounds like a wrist pin might have worn out. that will be a total rebuild. maybe a wrecker yard will have a used engine for under 1000

red1983

iTrader: (1)

That is the most logical explanation yet, thanks!

4wd4fun

i don't like being the bearer ofbad news but you've proven to yourself that somethings hitting the plug when you changed it and the new was damaged. its only logical that if something hit the plug it was the piston and its not hard to follow thru to the other things that can be damaged.

you wont know the truth of whats damaged until its torn down but its not looking good.

good luck

fierohink

When you replaced the #4 plug with a new one you said the new plug developed the same damage on the threads within a few miles. Did the misfire and poor performance return as well or just the physical damage?

Prior to replacing my head, due to a overheating issue, I had bad threads on the #4 cylinder from a PO that cross-threaded the head. Occasionally the plug would spin enough to come out of the motor. First time it happened I thouhgt the motor jumped time and was toast, until I got it home and threaded the plug back in.

These motors have aluminum heads, and if as you say the truck shows signs of abuse, which could be damaged.

You could run a compression test pretty easily to see if you have internal issues. Low compression would be an indicator. Then a leak down or pressurized chamber test would point to a bent valve either intake or exhaust.

blakefogt

different car I know, but The same thing happened to my bug, where i would replace a spark plug and then it would randomly start misfiring, only to pull the plug and see it was bent. turned out to be a washer that somehow got in my engine, and would sit on top of the intake valve, bounce around in there, ground the spark plug, then come back on top of the valve. found out by removing the intake manifold and finding a little belly button looking piece of metal. we assessed the damage with a little camera snake.. good luck!

benchernif

Cheap spark plugs (motorcraft, etc) are known to break apart in the cylinder housing. They'll stay threaded in, but the tip components will just fall apart. If you have something rattling around in your cylinder housing, you could keep doing damage to future plugs and your entire cylinder. Was anything missing from that first plug you took out? Did it look complete?

Just an idea...

Ben

red1983

iTrader: (1)

thanks for the ideas! The spark plug did look complete, but it horrible condition. I will try and post a picture here in a little bit.