I am about to replace LIM/UIM gaskets. Just few more questions.

[Langning]

This past Sunday I noticed small pools of oil on UIM (both side of #2 injector). I cleaned up the oil and only to see it again Monday night. Upon carefully examine the area, the oil is seeping out from the 2 lower intake bolts on both side of #2 injector. I was able to tighten the right-side bolt with 3/8 wrench. The outside bolt was impossible to turn enough because of the alternator and a square tab on the LIM. Right now, no more leaking from the inside bolt; small pool of oil is still forming on the left side as of this morning... I don't see oil in coolant or coolant in oil (good news)... I need to replace my LIM gasket and I have the overall concept of the procedure while unsure of some details.

1. Any special tool to disconnect the metal fuel rail to rubber fuel lines? Or a small screw driver will do the trick.
2. Do I remove UIM and throttle body as a single unit. Or throttle body must be detached and removed first?
3. Is removing alternator/tensioner necessary to get to LIM?
4. Do I need to buy 1 coolant elbow or 2? Do they come with new o-rings?
5. Where can I buy all fuel injector o-rings cheap?
6. Is the torque spec on the GM aluminum lower gasket 11 lb ft?
7. Does the aluminum lower gasket kit come with the silicon sealant and the side strips?

I ordered a new UIM off ebay last night and will call my local GM dealership for the aluminum lower gasket. I will try pepboys for the coolant elbow and injector o-rings and dexcool after work today.

BTW, my car is a 2001 3.8 GT with 95,000 miles.

[BNaylor]

Originally Posted by Langning

This past Sunday I noticed small pools of oil on UIM (both side of #2 injector). I cleaned up the oil and only to see it again Monday night. Upon carefully examine the area, the oil is seeping out from the 2 lower intake bolts on both side of #2 injector. I was able to tighten the right-side bolt with 3/8 wrench. The outside bolt was impossible to turn enough because of the alternator and a square tab on the LIM. Right now, no more leaking from the inside bolt; small pool of oil is still forming on the left side as of this morning... I don't see oil in coolant or coolant in oil (good news)... I need to replace my LIM gasket and I have the overall concept of the procedure while unsure of some details.

1. Any special tool to disconnect the metal fuel rail to rubber fuel lines? Or a small screw driver will do the trick.

You do not have to remove the fuel pressure and return lines from the rails. Otherwise a disconnect tool should be used.

2. Do I remove UIM and throttle body as a single unit. Or throttle body must be detached and removed first?

Recommended to leave TB on until you get te UIM off. But it can be removed before removing the UIM.

3. Is removing alternator/tensioner necessary to get to LIM?

Yes and must be done to remove 90 degree coolant elbow from LIM.

4. Do I need to buy 1 coolant elbow or 2? Do they come with new o-rings?

One. You can use aftermarket made by Dorman/Motormite.

5. Where can I buy all fuel injector o-rings cheap?

Advance, Autozone or NAPA.

6. Is the torque spec on the GM aluminum lower gasket 11 lb ft?

Yes.

7. Does the aluminum lower gasket kit come with the silicon sealant and the side strips?

Comes with the end seals (side strips). Use Permatex brand hi-temp silicone sealant on end seals only and gap between end seal and LIM port gaskets.

For further info see link below.

Click here

[Langning]

I will use the 2 PDF as guideline.

Here I found picture of the aluminum lower gasket (GM# 89017816). What is the small rectangular gasket (right end) for?

<img src ="http://i26.photobucket.com/albums/c120/BCGearhead/UIM%20Techinfo/ALUMINUMLIM.jpg" />

http://i26.photobucket.com/albums/c1...LUMINUMLIM.jpg

For the EGR valve outlet pipe, is there a gasket? Will I reuse it?

For the injector o-rings, is it 6 larger ones and 6 small ones? So I need 12 altogether, right? Do I need to know part# or size# or just tell parts person my car's model/year?

[BNaylor]

Originally Posted by Langning

For the injector o-rings, is it 6 larger ones and 6 small ones? So I need 12 altogether, right? Do I need to know part# or size# or just tell parts person my car's model/year?

Just give them your year/make/engine size.

Felpro has the lower and upper o-ring seal kits. Lower PN: ES71190. Upper PN: ES 71192. The AC Delco part number is 217-1427 and this kit from GM has both upper and lower in the kit.

[richtazz]

Don't buy the Motormite (Help! brand) coolant elbow, as they are problematic. Stick with the GM one at the dealer. The GM's are made of thicker plastic, and the Motormite ones are thin and split along the mold line.

[BNaylor]

Originally Posted by richtazz

Don't buy the Motormite (Help! brand) coolant elbow, as they are problematic. Stick with the GM one at the dealer. The GM's are made of thicker plastic, and the Motormite ones are thin and split along the mold line.

I agree Rich but we are a victim of our circumstances. The GM one is probably better. I just did a '98 Bonny VIN "K" UIM/LIM a few months ago and none of the local dealers had it in stock. Special order. We didn't have much time to get it back on the road but in the interim the Motormite elbow PN: 47065 is working fine. You just have to be careful installing it.

[wlkjr]

And don't take the hoses out of the tensioner-exchanger or you can order some expensive O-rings for that, about $10 apiece.

[Langning]

I ordered the GM-branded aluminum gasket & upper elbow host from GMPartsDirect.com today. May take a week to get here.

89017816 GASKET KI $36.78
24503423 PIPE ASM- $5.65 +$11 s/h

After work I picked the below items at Pepboys; they don't have injector o-rings in stock.

.5oz Permatex Hi-Temp RTV Silicone Gasket Sealant Item# 22073
.2oz Permatex Medium Strength Threadlocker (blue) PX#24200
HELP! coolant elbows PN #47065 $3.99 (cheap enough to keep an extra spare)
Hayes Repair Manual #24048 (Impala 95-2005). It covers the 3800 II engine in detail.

I will stop by autozone or advance auto to find the injector o-rings. I think I only need the lower set as I don't plan to separate the injectors from fuel rail/retainer.

Tonight I gave myself a thorough walk-thru on the steps and looked at/touched all the involved engine components and the LIM/UIM job should be very do-able. I also found oil slick on the driver-side dog-bone likely from valve cover. I will do the valve cover gasket tomorrow to get myself comfortable for the LIM/UIM job next week...

[BNaylor]

It sounds like you have a good plan. You are going to get a new UIM and throttle body gasket? I didn't see it mentioned. Also, if you plan on re-using the LIM/UIM bolts be sure to remove all the old threadlocker on the bolts before applying the new. Good luck!