Hey guys - newbie here -
Got a question on rebuilding a 1992 5S-FE. I have 375,000 miles on this engine with some pretty low compression #'s. I was wondering if you guys would recommend rebuilding, buying used, or what. I have found a kit on ebay for $225 with new pistons, rings, etc. I am not interested in anything special or more power, etc. I just want my reliable car back and still get 30 MPG.

I have had troubles and I replaced the head gasket years ago in the driveway with no good tools and consequently I made some mistakes, but it starts and runs ok now - it just doesn't stay running and has no power when it does go. Timing is within spec and it has new plugs, wires, and so on.

Got any advice for me? Please?!

 

What caused you to replace the head gasket, overheating?

What are the compression readings? Are the cylinder readings uniform or are one or two cylinders lower then the others?

Does the engine use more then 1 quart of oil per 1000 miles?

Is it possible for you to solve the current problems? Did you reconnect all the hoses, etc. correctly when putting the engine back together. Is the cam and crank pulley timing correct?

The issue is exploring the possibilities of fixing this engine before considering replacing or rebuilding it.

 

I did the compression check again and I was off before - cylinders 2, 3, and 4 are about 135-140. Cylinder #1 is about 50. I squirted oil in it and it jumped to 75 but no higher.
I replaced the headgasket due to overheating and never checked for warpage or anything. (I didn't have straight edges and didn't know to do this at the time) I did hook up a smoke machine and I have smoke coming from the head gasket area around the #1 injector.
I am not certain on the cam timing and I'll look at that this week. I might very well go ahead and pull the head again and check it while I'm at it. I had a heck of a time putting the whole thing together the last time as I had very few tools (No spanner wrench for one) and I was in my parents driveway. I have a shop now so I have no excuses!
I am pretty sure I got all the vacuum hoses back where they go. I marked everything up with tape before I took it apart.
Just out of curiosity, if I pull a spark plug boot while it's running, should it run worse? I can pull plug boot one and then two and the motor runs the same. If I pull #3 it dies. It acts like it's only firing on 2 cylinders. Will it run that way?

 

Typically even if the head gasket is blown then cylinder will still fire and put out some power.

Check for ign spark and try to determine if fuel is getting to each cylinder.

Remove the spark plugs. Look at each plug and note any differences. Are the plugs on the cylinders that don't seem to be working (no difference in engine performance when you removed the ign wire) loaded with unburned fuel, etc?

Remove the ign wire from the distributor, hold about 1/2 inch from ground point on the chassis, crank engine and check for spark. Should have healthy spark.

Check for ign spark at each plug wire.

If no fuel on the non-working cylinders did you connect the wiring to the injectors?

How was the condition of the cylinder bores when you had the head off, OK, scored, etc.

Guessing the issue is the head or head gasket installation. Suggest attempting to fix this. The compression in the cylinders is OK, the No 1 may just be effected by the head gasket. Guessing a little oil in any of the cylinders would raise it 25 psi.

This route is lot cheaper and easier then a engine rebuild which may not be required. If you have the cash, an automotive machine shop can check for warpage then face off the head if it is excessive, about $100.

Make sure you follow the head bolt torque procedures (use a torque wrench) or you will just create more problems.

 

My timing belt is off.....the alignment mark on the cam gear is off about 10 degrees or so from the little slash that you see through the hole with the crank pulley at 0 degrees on the timing tab. I'll fix that tomorrow and check valve clearances and see what happens.

 

New problem - the tensioner pulley bolt is stripped! I think I can lift the motor high enough to get to the threads and clean them up or go with a bigger bolt, or something. Anybody else ever deal with this problem directly? My concern with a bigger bolt is the tensioner hole might not be big enough........

 

This problem is common enough a Google search will turn up many hits. Review them then chose the procedure you think is best.

 

I have had troubles and I replaced the head gasket years ago in the driveway with no good tools and consequently I made some mistakes, but it starts and runs ok now - it just doesn't stay running and has no power when it does go.

 

I got the head off and sure enough - it's outta whack. The outer edges/corners are within spec (.002" according to All Data) but the middle in between and around the cylinders is over .011. I quit checking with the .011 feeler. I'm taking it down to a machine shop tomorrow and we'll see how it goes after that. In the mean time I'm going to look around on here and try to find out an easy way to adjust valve clearance. Those were all out of whack too........What are some good sources for the special tools and shims?

 

If the head can be resurfaced (not to warped) it can be done without taking the valves out.

Ask the machine shop and ask if they can set the clearance by mounting the cams on the head when still off the engine.

You will need a torque wrench to install the head bolts, no way around this.

An internet or Ebay search should turn up the tools. Search "Toyota shim tools."

The links below has some info on the process:

eBay Guides - Valve Shims for adjusting clearance--A primer

Adjustment

Sometimes it is possible to move shims around. You will need a caliper or micrometer to measure the thickness of the shims. If replacement shims are needed you need to measure the current valve clearance, the shim thickness then refer to a chart to obtain the replacement shim number. Shims are a Toyota dealer part.

Your machine shop person may be able to explain it to you.

When installing the cams make sure the service bolt is installed in the exhaust cam drive gears. This gear is two piece, it keeps the teeth of each gear aligned.

Make sure you REMOVE the bolt once the cams are installed BEFORE you rotate the cams!!