marty4runner

I recently bought a new timing chaing kit from engnbldr. I figured that while I was in there I would take care of my truck's occasional white smoke from the exhaust problem. It has also been diffucult to start sometimes and idling fairly rough. So rather than tear into the head and figure what the problem is, I just bought a whole new head (with upgraded cam and springs) from engnbldr also. I know it's probably more expensive that way, but we'll call it preventative maintainence. I will be doing the job this weekend and have been thinking...is that it? What if the problem is not in the head? What if I need new rings? What if I just needed a fuel injection cleaning or something? So I guess my question is...how can I find out what the problem is BEFORE I tear the motor apart, replace the head and T chain, put it back together only to have the same problem? I can fix things, I'm just not very sure how to diagnose. Thanks to all!
-marty

norcalsvx

put a fuel filter in there while you got the head off

marty4runner

good call, I will...

Marc

Do a compression test before changing the head.

If any cylinders are low put a nit of oil in them and redo it or do a leak down test.

dcg9381

In my experience the OHC setups last a long time, unless they are overheated or run with tight valves for extended periods of time.
The 22RTE heads are different, they put up with more heat and have thinner castings - they seem to fail more often based on what I've seen.

It'd be best to diagnose your problem BEFORE taking it apart. Once it's apart or not running, you're just guessing... All of the things you've mentioned above are valid and if you're a "peace of mind" kind of guy, they may be worth checking into.
Have the injectors cleaned/flowed by witchhunter.com
Tank your manifold to get all the nasty crapola out of it.
Rings.. Well, you can't tell after you've torn it down - it'd be best to do a leak down test up front and see what your results are. You can't see that you need new rings with the pistons in the bore. If doing new rings, I think you should do the entire thing as you're 90% there in terms of labor...

After reassembly, full FSM tune up procedure would be a good idea to get it running just like new. There are so many little things that cause it to run just a little funny, it's hard to guess without testing components.

marty4runner

thanks for the info. What I'm not sure of....how do I do a compression or leakdown test anyway?

91TPU

go to an auto parts store and buy a compression test kit, it has a threaded peice that fits into the spark plug hole. im sure the actual directions are much more detailed then this, but its just a basic overview, and isnt a leakdown the same with a bit of oil put in the cylinder first?

dcg9381

Leakdown is a similar tool, goes in the spark plug hole.
It has two gauges - one for the pressure going into the cylinder and one for the pressure that the cylinder will hold. The difference in % is "leakdown" - by listening to where the air is coming out, you can often determine where the leak is. Good for diagnosing ring issues, valve problems, and the dreaded HG issue.

marty4runner

Is it easy to replace my rings? Cheap? Since I will be in there anyway, maybe I should do that and that way rule out everything!

dcg9381

Replacing rings isn't too hard, it requires a ring compressor or the help of about 3 hands. I wouldn't recommend replacing rings on a non-machines block however.. There are those that do "budget" rebuilds that might disagree.

If you're going to the trouble to replace rings, you're only a couple of hours out on a complete teardown and rebuild that could (if done correctly) last you another 200k miles.


Do a leak down - see what your % is.. After that, decide what you're going to do.

surf4runner

go big or dont go at all.