Intake Manifold Repair Question???

I have a coolant leak on my 99' Park Avenue 3.8L.

I have found where it is coming from. When the car is running coolant is seeping out from under the Lower Intake manifold, of the passenger side just above the Water Pump.

Now Im thinking that I just need to replace the Lower manifold gaskets. The Lower Manifold shouldnt have to be replaced because its aluminum/metal and its not just gonna go bad right????

Ive heard of people having to replace the Upper Manifold too, but it Im not having a leak from there I should be alright with just leaving it as is????

Also does anyone know of a website or somewhere that may have a step-by-step, or pictured diagram for how to go about this???

I was already planning on selling the car in a few months, so I dont want to put a ton of money into it, but I want it running right. Im deffinetly not gonna pay a shop $800 which I was quoted.


Thanks for the help

I have a coolant leak on my 99' Park Avenue 3.8L.

I have found where it is coming from. When the car is running coolant is seeping out from under the Lower Intake manifold, of the passenger side just above the Water Pump.



Are you sure the leak is NOT from the o-rings on the 90 deg. tube that comes out of the lower intake and goes into the housing for the belt tensior and out to the heater hoses at the other end of the tensioner?

Check oil for any signs of coolant in it from internal leak. It will appear milky rather than clear and dark. If you see signs, drain oil and refill with cheap oil and run a minute or two to get bearings covered by fresh oil. After replacing UIM, LIM, etc., you'll run briefly and replace the cheap oil again to purge coolant that got into the oil and will damage bearings.

If you do this, I assume the UIM has not been replaced. Have you owned the car since new? There may be circular date marks on the UIM that show the year of manufacture. Replacement UIMs don't have these--at least not that I noticed.

Replace the LIM gaskets with the metal framed ones from GM. If the upper were recently replaced you might replace only the gaskets under it and to the throttle body, but it would be penny-wise and pound-foolish to NOT replace the UIM while it's off. The EGR tube area will have deteriorated from heat and potentially will leak in the future. Dorman, APN, and others make modified UIMs. The Dorman comes with a smaller metal EGR tube that fits into the LIM metal and sticks up into the upper and improved sealing rings around the coolant tubes that go to the throttle body. The smaller EGR tube leaves more air room around the hot spots. APN, I believe, has a metal sleeve inside the upper to help spread the heat from the hot exhaust coming up through the EGR tube.

There are places on the web where people have listed steps for removal. I suggest organizing all screws and bolts into small groups and labeling them. The injectors lift up (wiggle out) and can be tied out of the way folding them back onto the firewall area. Replace injector o-rings, they came with Dorman that I had bought. If you find signs of leakage internally, change oil after motor is running again to get coolant contaminated oil out.

Are you sure the leak is NOT from the o-rings on the 90 deg. tube that comes out of the lower intake and goes into the housing for the belt tensior and out to the heater hoses at the other end of the tensioner?

Check oil for any signs of coolant in it from internal leak. It will appear milky rather than clear and dark. If you see signs, drain oil and refill with cheap oil and run a minute or two to get bearings covered by fresh oil. After replacing UIM, LIM, etc., you'll run briefly and replace the cheap oil again to purge coolant that got into the oil and will damage bearings.

If you do this, I assume the UIM has not been replaced. Have you owned the car since new? There may be circular date marks on the UIM that show the year of manufacture. Replacement UIMs don't have these--at least not that I noticed.

Replace the LIM gaskets with the metal framed ones from GM. If the upper were recently replaced you might replace only the gaskets under it and to the throttle body, but it would be penny-wise and pound-foolish to NOT replace the UIM while it's off. The EGR tube area will have deteriorated from heat and potentially will leak in the future. Dorman, APN, and others make modified UIMs. The Dorman comes with a smaller metal EGR tube that fits into the LIM metal and sticks up into the upper and improved sealing rings around the coolant tubes that go to the throttle body. The smaller EGR tube leaves more air room around the hot spots. APN, I believe, has a metal sleeve inside the upper to help spread the heat from the hot exhaust coming up through the EGR tube.

There are places on the web where people have listed steps for removal. I suggest organizing all screws and bolts into small groups and labeling them. The injectors lift up (wiggle out) and can be tied out of the way folding them back onto the firewall area. Replace injector o-rings, they came with Dorman that I had bought. If you find signs of leakage internally, change oil after motor is running again to get coolant contaminated oil out.


You are right it is coming right out of that fitting that goes into the LIM. Can that 90 degree fitting just be replaced. if so what has to be dissasembled, the belt tensioner, or more.

Also does the 90 degree tube need to be replaced or just an o-ring. and how does it come out, any bolts or just pulls out.

Also since it is coming right out of there that means no coolant should have been able to get into the oil correct???

Thanks

You are right it is coming right out of that fitting that goes into the LIM. Can that 90 degree fitting just be replaced. if so what has to be dissasembled, the belt tensioner, or more.

Also does the 90 degree tube need to be replaced or just an o-ring. and how does it come out, any bolts or just pulls out.

Also since it is coming right out of there that means no coolant should have been able to get into the oil correct???

Thanks

That's good news. A real leak means it's not going into the combustion chamber and oil gallery.

You have to remove the tensioner base with the bracket on it. There are several bolts. One I believe you access through a hole in the pulley. The angle plastic tubes should all be replaced. They are available at the parts store in a package. I don't know if the o-rings are in the package or separate. Replace all the plastic 90 degree elbows. They are brittle with age. Clean o-ring slots carefully. Some people use a little silicone sealer on the o-rings.

That's good news. A real leak means it's not going into the combustion chamber and oil gallery.

You have to remove the tensioner base with the bracket on it. There are several bolts. One I believe you access through a hole in the pulley. The angle plastic tubes should all be replaced. They are available at the parts store in a package. I don't know if the o-rings are in the package or separate. Replace all the plastic 90 degree elbows. They are brittle with age. Clean o-ring slots carefully. Some people use a little silicone sealer on the o-rings.


great thanks, sounds alot better then tearing the motor apart, I will be back if I run into any questions as I go, or update when Im done this weekend

Thanks again

Click Here (http://www.automotiveforums.com/vbulletin/showthread.php?t=915511)for more details on replacement of the elbows.

gpuvalowski,

Please try to keep the same thread when posting issues that have the same basis, origin or questions. Your other post is at the link below.

Otherwise all it does is cause confusion, possible redundant answers and more work the the Moderating Staff. Your future cooperation is appreciated.

http://www.automotiveforums.com/vbulletin/showthread.php?t=946723

gpuvalowski,

Please try to keep the same thread when posting issues that have the same basis, origin or questions. Your other post is at the link below.

Otherwise all it does is cause confusion, possible redundant answers and more work the the Moderating Staff. Your future cooperation is appreciated.

http://www.automotiveforums.com/vbulletin/showthread.php?t=946723


sorry about that it wont happen again

Click Here (http://www.automotiveforums.com/vbulletin/showthread.php?t=915511)for more details on replacement of the elbows.

Good post Bo. It beats speculating or getting erroneous advice. :uhoh:....:lol:


To the OP if you would like a tech procedure on the UIM/LIM job just send either HotZ28 or me a PM message with regular email address so the file can be sent as an attachment.

replacing the plastic elbows has seemed to fix the problem. Thank you to all that helped point me in the right direction

FYI- A quick way to remove the broken elbow from the manifold or tensioner, is to use a hacksaw blade to cut 3 channels around the o-ring/plastic. You don't need to cut all the way through them. This will allow enough 'play' in the o-ring/plastic so you can then hook it out in one piece. Takes less than 5 minutes. No drilling or shavings.

FYI- A quick way to remove the broken elbow from the manifold or tensioner, is to use a hacksaw blade to cut 3 channels around the o-ring/plastic. You don't need to cut all the way through them. This will allow enough 'play' in the o-ring/plastic so you can then hook it out in one piece. Takes less than 5 minutes. No drilling or shavings.
Good tip but this thread is a dead 3 year old situation, might check the dates first, thanks.