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LIM being changes this weekend want ot see if I have everything covered

7

71gs3504sp

New member
Hi

My 99 GP GT just hit 99k miles on it and will be doing the LIM replacement this weekend. To date it’s still all original since purchasing it new with the exception of regular maintenance of engine oil/filter, antifreeze/thermostat, air filter, spark plug/wire and transmission oil/filter.

Here is a list of parts I am replacing while I am doing the LIM.

- Thermostat/Gasket 195 degree
- Antifreeze Yellow with Distilled Water
- Valve Cover Gasket and Grommets
- Aluminum Coolant Elbows
- LIM Gasket
- UIM Gasket
- Serpentine Belt
- Water Pump
- Heater Hoses
- Radiator Hoses
- Throttle Body Gasket
- 5 Quarts of Oil and Filter

I am going to flush out the old Dex coolant prior to begin the LIM change. If I change the water pump prior to LIM gasket will all the coolant be removed from of the LIM? I am also going to clean out the UIM, LIM and Throttle Body.

Let me know if I am missing anything.

George
 


Add another quart of oil to use to wash the lifter valley out after you remove the LIM as some coolant will likely spill. Then change the oil BEFORE you start the car.

Also need the black or GM gray RTV on there for the 4 corners where the LIM meets the heads.

Proper bolt sequence/torque specs for the LIM/UIM?

Oh, and if you haven't already researched this a ton, don't overlook the 2 hidden bolts holding the LIM to the block. They are usually covered in a pool of oil and you will pull your hair out trying to find them.
 
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[/URL] will save u alot of time!! greatest investment ever! lol
 
atj8 has a very good point, some sort of container to sort the bolts will really help during reinstallation. Write what the bolt goes to on some masking tape and put it on the bottom of the slot.

And definitely seal those threads, the white sealant sold at autoparts stores will work, the high temperature stuff.
 


a torque wrench is nice too.

pull the dog bones, you need to remove the coil pack bracket, to get to the valve cover off, so once you pull the lower rad hose most of the coolant will drain, then rock the engine to the back, hold it there, then to the bumper, hold it there, this will drain the lim. theres a lip on the inside, so if you lift the lim up as level as you can you may get lucky like i did and not spill a drop of coolant into the lifter valley.

i did no oil change afterwards. still running.

dont forget the thread sealant on the lower lim bolts, and the 4 long bolts to the water pump if you change that, water pump needs the p/s pump to be unbolted to get one damn long bolt out. some have said they took the lower bolt out, then loosened the upper bolt, then were able to rotate the pump to the side and get the bolt out.

you n/a guys have 2 hidden lim bolts too, inside the lim.

and you may want to mod your lim, aka seal off the 2 coolant ports. that way the upper intake can never leak on you.
 
71gs3504sp said:
Hi

My 99 GP GT just hit 99k miles on it and will be doing the LIM replacement this weekend. To date it’s still all original since purchasing it new with the exception of regular maintenance of engine oil/filter, antifreeze/thermostat, air filter, spark plug/wire and transmission oil/filter.

Here is a list of parts I am replacing while I am doing the LIM.

- Thermostat/Gasket 195 degree
- Antifreeze Yellow with Distilled Water
- Valve Cover Gasket and Grommets
- Aluminum Coolant Elbows
- LIM Gasket
- UIM Gasket
- Serpentine Belt
- Water Pump
- Heater Hoses
- Radiator Hoses
- Throttle Body Gasket
- 5 Quarts of Oil and Filter

I am going to flush out the old Dex coolant prior to begin the LIM change. If I change the water pump prior to LIM gasket will all the coolant be removed from of the LIM? I am also going to clean out the UIM, LIM and Throttle Body.

Let me know if I am missing anything.

George
Click to expand...

Well guys just got the job completed today. Started at 8 am and finished at 6 pm. Lower gasket still looked good for being original. Did not have any issues with antifreeze sludge in the intake or gaskets. I could not believe how dirty the UIM ,LIM, especially the backside of the TB was, it took me a while to get it down to metal or plastic instead of black sludge. I also replaced all the heater and radiator hose and what a PIA the metal spring clips were to get off!

George
 
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71gs3504sp said:
Well guys just got the job completed today. Started at 8 am and finished at 6 pm. Lower gasket still looked good for being original. Did not have any issues with antifreeze sludge in the intake or gaskets. I could not believe how dirty the UIM ,LIM, especially the backside of the TB was, it took me a while to get it down to metal or plastic instead of black sludge. I also replaced all the heater and radiator hose and what a PIA the metal spring clips were to get off!

George
Click to expand...


An issue arised since completing LIM replacement. Its seems it would not get out of high idle and running about 1500rpm in netural and 1100rpm in drive. Also a code came up noting high idle issue. It does run good but seems a little underpowered than before I started the teardown. Hope someone can direct me what to look for and do.

Thanks George
 


Remove both the throttle and cruise cables from the TB. If the idle is normal, the issue is in how the cables are sitting on the strut tower. The loop they do up there can cause this.
 
hmm didn't think of that bill. I'll have to put that up in the memory for if I ever run into this issue.
 
Had a local who put on a ZZP tb and it happened. Once it sets the code for high idle, it means that it's tried to bring it down by all means.

Since he had this off.. He probably cleaned the TB and it shouldn't be gummed up and sticking. He would have removed the cables or at least moved them around. It was so nice when I pulled those two cables and it idled normal.
 


BillBoost37 said:
George... I have broken a lot of stuff to gain knowledge. Ask anything..I might just have answers...lol
Click to expand...

Bill

You wouldn't believe this! I undid both throttle/cruise cables and idle went back to normal. I am assuming the throttle cable is the one with the metal stud at the end of the cable and the cruise control cable has the black plastic clip. If I am correct then the throttle cable is not the problem. I believe its the cruise control cable that needs to be adjusted with the black clip at the end of the cable. So how the %*#$ do you undo the clip to make the adjustment?

George
 
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its been a while since i did mine but theres a clip that locks it on the TB. if you push it to wot, then hold the cable the cable will come off the groove it lives in. then work on unlocking the end clip, or re do it so its on right and dont pull on it at idle.
 
George...I'd be lying if I told you it was my first time.

Here's how you fix the issue. Diddle the cable as it does it's loop on the strut tower and once idle is fine.. stop touching it. Likely you'll never be able to get it to screw up like that again.
 
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