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L36 - LIM gasket, VC gaskets.. questions

C

codyAK

New member
So, my sister drives a 2001 grand prix GT.
She told me she has been losing coolant, and that she thinks she might be leaking oil.
So I popped the hood and pulled off the engine cover, and the pics that are in this thread are what I found.

Obviously it looks like she needs a LIM gasket replaced, and valve cover gaskets replaced. I will probably have the coolant elbows on hand to replace since they're likely to break. Is there anything else I should replace while I'm in there?
Is there any way I can determine if the UIM needs to be replaced? I have read that the UIM in this L36 commonly fails.

I have never torn into a motor at all, but I think I am going to try to replace these for her, so this will be a first for me if anyone has any advice.

I'm hoping to get a parts list together so I know everything I will want to have on hand,
LIM Gasket
Valve cover gaskets
Coolant elbows
5+ quarts of oil
razorblades
carb cleaner

Any recommended brands for parts, or brands to stay away from?

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Yep, get the aluminum LIM gaskets for sure.

Make sure when you get the valve cover gaskets you get the grommets for the bolts as well, or they will leak again. Fel-Pro's are nice. You could get the new aluminum coolant elbows as well. Might want to replace the injector o-rings if your UIM gasket set does not come with them. Now would also be a good time to plug the coolant ports on the LIM to avoid the UIM cracking and feeding coolant to all the cylinders sometime in the future. There is a write-up on here somewhere, so give it a search.

Would also be a good time to remove the throttle body and clean it till it shines. And as far as checking the UIM, I would just look for cracks around the bolt holes, and check the area on the inside where the EGR pipe comes up out of the LIM. This is where it usually cracks. Also check the area where the TB bolts to the UIM once you remove the TB.

You will need enough oil and filters to do 2 changes, and at LEAST 1 quart of oil to dump into the lifter valley to wash it out before reassembly. This will ensure that any coolant that got in there during removal (which there will be some, unavoidable) is flushed into the pan. Then you change the oil and filter BEFORE you start it up, let it run for about 10 min or so, then shut it down and change the oil and filter again. Usually recommend using the cheaper oil/filter for the first 10 min. run, then on the 2nd change use the filter and oil you usually do. The reason for all of this is to keep the bearings in the bottom end happy and to not spin one in 10 miles. Since it's already loosing coolant internally you need to be sure that you get all of it out, hence the 2 oil changes.

It's not a tough job, even though it looks like a lot of things to remove. Just take your time and be sure to clean everything. Oh, and don't miss the 2 hidden bolts on the LIM, as they will likely be covered in oil. And be sure to cover up the intake ports once you have the LIM off to avoid dropping anything in there. Could be bad news if you loose a bolt, lol.... trust me :th_winking:

Add some gasket sealer (black or GM gray) to that list, as you will need to put some on all 4 corners of the valley gasket where the LIM meets the heads.
 
What do you mean plug the coolant ports?

I just changed the UIM & LIM on our L26 2004 Grand Prix and upon disassembly we found some gunky substance in two opposing ports in the heads. We thought somebody has poured stop leak in the engine at some point, so we cleaned out the ports.

Now I'm wondering if we should have left that gunk in the ports based on what I'm reading on this thread. I did notice while cleaing the LIM that the clogged ports in the heads matched up to a spot on the LIM that didn't have a port.

So far everything seems normal, but now I'm worried that we removed something we shouldn't have.
 
Appreciate the advice thus far! I plan on attempting this next Saturday if everything goes as planned.

If I plug the UIM, I should have no worry about potentially needing to replace it, correct?

This is my newest parts list:
LIM Gasket
Valve Cover gaskets
Coolant elbows
TB Gasket
gasket sealer
11+ quarts of oil
razorblades
carb cleaner


04silverprix said:
What do you mean plug the coolant ports?

I just changed the UIM & LIM on our L26 2004 Grand Prix and upon disassembly we found some gunky substance in two opposing ports in the heads. We thought somebody has poured stop leak in the engine at some point, so we cleaned out the ports.

Now I'm wondering if we should have left that gunk in the ports based on what I'm reading on this thread. I did notice while cleaing the LIM that the clogged ports in the heads matched up to a spot on the LIM that didn't have a port.

So far everything seems normal, but now I'm worried that we removed something we shouldn't have.
Click to expand...
Check out these two threads by Bill:
http://www.grandprixforums.net/97-03-na-l36-uim-failure-60667.html

http://www.grandprixforums.net/how-mod-lim-46931.html



 
Last edited:
Okay I read Bill's threads and that is different than what I encountered with my Series III "L26" engine. I think cleaning out the gunk out of my heads was the proper move. I think it was stop leak or something that built-up in the ports.

I have an aluminum UIM, so what is discussed with Bill's threads is for the plastic UIM.
 


dsmuts said:
The replacement uim from a parts store is supposed to be corrected to not fail.
Click to expand...

Well, maybe I will just replace the UIM - I have just thought I read it still fails.. I'm not sure though


Current parts list.. Am I missing anything?



valve cover gaskets - Buy Felpro Valve Cover Gasket Set VS 50080 R at Advance Auto Parts
valve cover grommets - Buy Felpro Grommet Set ES 72833 at Advance Auto Parts
aluminum elbows - Buy Dorman - Help Heater Hose Elbow Aluminum 47065HP at Advance Auto Parts
195* t-stat - Buy Stant Superstat™ Super Premium Thermostat, 195 Degrees Fahrenheit 45849 at Advance Auto Parts
lim gasket set - Buy Felpro Intake Manifold Gasket Set MS 98014 T at Advance Auto Parts

And then I'm debating whether to just replace the UIM with this:
Dorman 615-180 Intake Manifold : Amazon.com : Automotive

OR if I want to just replace the gasket, and then plug the coolant holes:
Buy Felpro Plenum Gasket Set MS 95812 at Advance Auto Parts
And then I would also have to buy a tap and two threaded plugs.

I would rather just replace the UIM, but I don't want to replace it with that one and then have it fail.

And of course oil, carb cleaner, coolant all from a parts store
 


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