Another 3800 upper intake manifold question or 2
 

I am in the process of replacing the upper intake manifold. I have the shop manual but do not find any torque specs for the upper intake manifold bolts. Does anyone know - for certain.

Second question. I broke the twist fitting on the top of the EGR tube. Any good sources for used? Or any good way to fix?

Thanks,

Neal Lewis

For the broken tube: Have you tried a auto parts store? They might have it, or you can try the dealer. More than likely its overpriced there. You can also try the junk yard.

I would be happy to pay the cost of a new one from a dealer. But GM has discontinued the EGR tube for 1995 Buick LeSabre.

After market parts stores are no better. And most salvage yards want me to buy the whole engine.

The problem with a salvage yard unit is that it would be the same age as my current one. The plastic is brittle and the twist fitting broke.

I have finished replacing the upper intake manifold (uim) and lower intake manifold (lim). In the process I replaced the gaskets for the lim. The torque spec. for the uim and lim are 11 lb. ft. (15 Nm) each. This is per #43-61-08A: SMU - Section 6A - Revised Torque Spec - (Jan 1, 1995). I had to track that down at the Buick dealer. I also have torque specs, pictures and video for all of that procedure.

I replaced the throttle position sensor (tps) and the speed sensor (ss) - not the crankshaft sensor. I also replaced the bypass hose and all of the vacuum lines..

The locking head on top of the EGR tube going into the uim snapped one of the tabs that holds it in the uim. Those EGR tubes have been discontinued by GM. They are not available as an after market item.

Most salvage yards will only sell the complete engine because that tube is critical for the engine to operate.

For the time being, I have put hi-temp silicone seal around the locking head and the uim. That seems to be sealing it OK.

I am still getting a shuddering as it goes up hills or accelerates. I am not sure if maybe I have head gasket problems, or it is something else. The spark plugs need to be replaced as do the spark plug wires. It would be good to replace the fuel pressure regulator (fpr). I also want to replace the mass air flow sensor (maf). The engine has 152,000 miles but idles well and up until now has been very dependable.

If there is not coolant going into the cylinders through bad head gaskets, then the only other thing I can think of would be the crankshaft position sensor (cps). I can not do the work of testing and installing a new dynamic balancer, at least it looks beyond my capability. I have removed and replaced heads, but this looks more finicky and precise.

I plan to watch the coolant reservoir for the next few days to see if the level goes down. If it does not go down, then the problem may lie outside of coolant being sucked into the cylinders.

Has someone had similar problems? I will be glad to write up the procedure, add pictures and video and share it with the group. Let me know if that would be a help.

Thanks,

Neal Lewis

Before you go replacing a bunch of good parts, I can tell you, anti-freeze is detrimental to oxygen sensors and you may need to replace those first and see what results you get after that.

Thanks for the advice. The hot oxygen sensor is easy to get to and relatively inexpensive.

The car does seem to be running better. There is a possibility that there was water in the gas.

It was in the car port for about 4 months. Considering the amount of anti-freeze that went past the sensor, it won't hurt to replace it.

Thanks again.

Neal Lewis