Tranny and engine woes

[89GMCSuburban]

Man, you fix one thing and then there's always something else. After dumping $1,100 into the rear-end, the tranny is acting funny and the engine is smoking. First thing's first, the trans is acting strange.
At about 45 MPH in OD, if I hit the gas more than half-way it starts to jerk the truck like someone was rapidly pushing and pulling the back of the truck. I've also had a loud knocking noise coming from the engine or trans that only happens in reverse. It sounds like someone knocking a wrench on the tranny inspection cover. Anyway, the tranny fluid is orange, not red. It has no problems shifting. You think it's the torque converter? My 87 S-10 Blazer did this when the TC was going out.
The motor, after a tune up, now very lightly smokes. The smoke is white. I know, you're saying a blown head gasket, but it's not overheating and there's no water in the oil or oil in the water. Power is still excellent. What is wrong with it?? Thanks for any help guys!!

Red 1989 GMC Suburban SLE V1500 - TBI 350, 700R4 w/ shift kit, Quad-shock front, 31/10.50/15 Pro Comp MT, 4.10 gears, Duals off cat

 

[dyeager535]

Sounds ALMOST like your torque converter clutch solenoid is perhaps acting up....have you tried the same speed in D? (3rd)

May or may not be the problem, but unplugging the electrical connector (4 prong, unsually only 3 wires though) and re-testing will let you know if its the TCC (or that circuit) thats causing your problems. Its also pretty easy. Eliminate the easy stuff first : )

Could also be something in fuel delivery or the management thereof, like TPS, but again, not certain. Is it setting codes?

Dorian
My tech/links page: <a target="_blank" href=http://www.dorianyeager.com/index2.html>www.dorianyeager.com/index2.html</a>
Why insist on counting when the ring gear has the tooth counts stamped in?

 

[89GMCSuburban]

In D at the same speed, it doesn't do it.
The computer is not setting any codes, and that's what is so strange.

Red 1989 GMC Suburban SLE V1500 - TBI 350, 700R4 w/ shift kit, Quad-shock front, 31/10.50/15 Pro Comp MT, 4.10 gears, Duals off cat

 

[Burbinator]

A blown head gasket doesn't always pass coolant into the oil. It could be just enough to burn up and not pass. One thing you could try is to remove the cap while the engine is running (while it's COOL) and let it come up to normal op temp. If the coolant starts to "percolate" and/or smells like fuel, you have a blown gasket. Next, do a compression check to see what side you get to pull off, but you figure the other side has as many miles on it and it doesn't take much to pull both after it's all apart.

Good luck and let us know!

Haze gray and underway...<font color=blue>or blue, in my case.</font color=blue>
<a target="_blank" href=http://community.webshots.com/album/26246038MbQsYWKcbo>U.S.S. Nimitz II</a>

 

[txbartman]

On the engine, could it be oil leaking past the seals on the valves ever so slightly? Just a thought.

Brian
Check out <a target="_blank" href=http://tx85gmcguy.alloffroad.com>My Jimmy</a> with all her projects!

 

[89GMCSuburban]

For the compression check, how much PSI is normal for the motor and how many times do I let it crank before I take the reading? If it's a head gasket, I'm probably just gonna rebuild the motor. It does have a lot of miles on it.

Red 1989 GMC Suburban SLE V1500 - TBI 350, 700R4 w/ shift kit, Quad-shock front, 31/10.50/15 Pro Comp MT, 4.10 gears, Duals off cat

 

[Burbinator]

I can't recall what a "normal" PSI level is...maybe someone else can help me? You're looking for a cylinder that has noticeably less pressure than the rest. The best way to do it, if your compression tester isn't equipped with a peak lock, is to have a buddy crank it (pull the coil "hot" wire) and watch it peak and record the reading. Do that for all 8...

Have fun!

Haze gray and underway...<font color=blue>or blue, in my case.</font color=blue>
<a target="_blank" href=http://community.webshots.com/album/26246038MbQsYWKcbo>U.S.S. Nimitz II</a>

 

[dyeager535]

Basically IIRC, the PSI isn't as important as all cylinders being within 10% or so of each other PSI-wise. You are looking for one or two cylinders with a large difference compared to the other ones.

I forgot to add that the knocking could also be due to loose torque converter bolts or broken flexplate. I mention that only because I have heard it, but I also want to say that if that every one I have seen that is broken, or loose bolts, made the noise ANY time the engine was put under strain, (never tried in reverse though) most noticeably say, trying to climb a steep hill from a dead stop...

Dorian
My tech/links page: <a target="_blank" href=http://www.dorianyeager.com/index2.html>www.dorianyeager.com/index2.html</a>
Why insist on counting when the ring gear has the tooth counts stamped in?

 

[kilroy]

My 90 hits 165 psi, with 4 to 5 cranks

 

[89GMCSuburban]

The Flexplate isn't cracked, I checked that. The TC bolts, I'll have to try those. Anyway, my 87 Blazer had the same jerking problem when the TC was going out, is it possible that that is the problem? Could the TC even be making the noise?
Today, I pulled off the PCV valve andd oil filler at operating temp and the oil filler hole was smoking while the PCV one wasn't. Does that mean the gasket leak is on the oil filler head?

Red 1989 GMC Suburban SLE V1500 - TBI 350, 700R4 w/ shift kit, Quad-shock front, 31/10.50/15 Pro Comp MT, 4.10 gears, Duals off cat

 

[89GMCSuburban]

ttt

Red 1989 GMC Suburban SLE V1500 - TBI 350, 700R4 w/ shift kit, Quad-shock front, 31/10.50/15 Pro Comp MT, 4.10 gears, Duals off cat