PontiacBonnevilleClub.com

Hi Guys,
The time has come to replace the UIM gaskets on my '02 Park Ave Ultra. It has roughly 115,000 miles, and the engine runs fine, but I looked under the hood today and I saw wet gooey residue in multiple areas on the top of the engine - for example, around some of the fuel injectors.

I already bought the aluminum GM lower intake gasket set, a GM supercharger base gasket, and valve cover gaskets in preparation for the 'fun' ahead of me. I'm thinking of doing the work this weekend.

I've previously worked on two previously owned 3800 series I supercharged Bonnevilles (replaced the superchargers, water pumps, etc.), I've worked on a normally aspirated '99 Bonneville SLE (replaced the upper intake with a Dorman intake), and on the '02 Ultra I've already replaced both of the coolant elbows with the aluminum versions, and I've completed other miscellaneous repairs, so I've done some work on the '02 Ultra since I bought it a little over 2 years ago. But I've never removed the supercharger on a supercharged Series II (the '02 Ultra).

I looked at the LIM replacement instructions in the Techinfo section in preparation for the work, but I'm wondering if there are any special tips, tricks, or things to note when replacing the LIM gaskets on a supercharged Series II engine. For example, I'm not familiar with the 2 fuel fittings on the top of the supercharger. And I've noticed that the injectors on the '02 Ultra are placed in recesses in the valve cover gaskets as opposed to being placed closer to the supercharger.

Any words of advice?

Thanks.
-Bill

I can't help with the fuel fittings, but other than that everything is simple. From what you said you've done to the other 3800 cars, you should have no issue with this project. Just take your time and be thorough.

You shouldn't need to remove the fuel lines from the rails. Just carefully set it aside.

The injectors go into the bosses on the heads, it doesn't come apart any differently than a N/A car.

Go slow, take your time, bag and tag parts. Torque specs are in Techinfo. You're familiar with it. It helps to siphon as much coolant out of the LIM as possible, reduces the chance of spilling any into the valley. Other than that, it's pretty self-explanitory.

Thanks for the info about moving the fuel rail out of the way.

I may decide to do the work tomorrow, before the holiday.

I need to buy a set of injector o-rings. I don't remember, do the injectors need 2 different size o-rings, 1 size for mating to the fuel rail and 1 size for mating to the intake?

While I'm at it, I'm thinking of also replacing the water pump and the upper and lower radiator hoses...unless you guys think the water pump will last much longer than 115,000 miles. I already replaced the thermostat earler this year when I replaced the coolant elbows.

The O rings should all be the same size.

O-rings are NOT the same size.

Really? I've only ever been given all one size for the injector o-rings...

It really depends on the application. I've seen it both ways. But RockAuto does sell a kit that has both.



No way to really know until you get your old ones off.

L67 injector o-rings should be the same size on both sides -they didn't change injectors on SII L67's at any point 1996-2005.

Also, DO NOT use FAIL-PRONE (FelPro) lower intake manifold gaskets -use GM part # 89017816 or 89017825
Coolant elbows 47065HP (Dorman Help section at most any parts stores).
Use PERMATEX WATER PUMP & THERMOSTAT HOUSING RTV/SILICONE as a lubicrant for the coolant elbow o-rings to prevent the o-rings from tearing -it also is an extra layer of protection against leaky coolant elbows.

I made notes when I did mine. Right or wrong this is what I did and worked fine. I have another to do.


2003 Bonneville LIM gaskets and UIM manifold replacement


1) Remove both heater core hoses from tensioner assembly. Remove lower radiator hose from pump. Remove thermostat housing leaving hose attached. Remove overflow bottle.
2) Using garden hose flush heater hoses both ways, engine through thermostat housing and radiator through cap and upper hose.
3) Unhook positive cable from battery.
4) Remove 3 rear plug wires from coils, label and place toward rear of engine
5) Remove alternator wire and pull under 3 remaining plug wires.
6) Remove tensioner assembly and unplug alternator. Remove coolant elbows making sure to get broken off plastic pieces. Clean bores in tensioner and engine with steel wool/ 220 grit sand paper. Clean with brake clean.
7) Remove intake boot and sensor wire. Lube boot when putting back on for easy assembly.
8) Remove fuel rail and many connectors. Can leave fuel rail attached. Just wire back to wiper. Clean injectors with carb clean. Lube orings for easy assembly.
9) Remove metal EGR shield
10) Remove large vac line on rear LIM.
11) Remove throttle cables
12) Remove Plenum and throttle body as assembly. Remove TB from plenum and clean well. Make sure to take out MAF to avoid damage. Use blue loctite on plenum bolts. 89 in-lbs.
13) Remove EGR pipe. Do not just take off one end. Spray with rust lube ahead of time.
14) Remove TB bracket and grind relief for easy assembly.
15) Remove front and rear auxiliary brackets for easy LIM removal. Ones with large torx head.
16) Remove intake manifold. Make sure you get all bolts. 2 hidden ones. Be careful because coolant can pour into engine. Get paper towel underneath while removing. Pressure wash and clean gasket surfaces with 220 grit including heads on engine. Clean LIM bolts well and apply RTV on threads prior to assembly. 132 in-lbs.
17) Reverse order for assembly. Make sure to put high temp RTV at (4) head to block transition areas.
18) Seems to be plenty of water left in engine and radiator so just add straight anti freeze.

Fuel injector o-rings ES70599

Pretty easy job. I pulled the relay for the fuel pump and ran it out and removed the injectors and rails when i did mine. you need the quick detach tool to get them off. its a easy job if you take your time. drain your coolant down to keep the fluid from leaking into the cylinders. and there are a couple bolts hidden inside the lower intake manifold on the passanger side of the motor.

S

Help! It looks like I have very bad news (for me).

I did all of the work on Wednesday. I replaced the LIM gaskets (aluminum GM version), supercharger gasket, water pump, and valve cover gaskets. I removed and re-used the aluminum coolant elbows because I replaced them eariler this year , I applied sealant on the orings to make sure they'll seal. I put everything back together except for reinstalling the throttle body because I didn't have a throttle body gasket.

Note that defore I did the work, I drained the coolant from the radiator. More coolant came out (as expected) when I replaced the water pump.

I haven't refilled the coolant or tried to start the engine since Wednesday; the car has been parked on my driveway since then.

Today I was going to go buy the throttle body gasket and reinstall the throttle body. Before I planned to go to the auto parts store, I took a look at the engine.

Here's the bad news: there's something wet on the upper side of the rear passenger side of the LIM, around the rear driver's side corner. Note that before I began all of this work I assumed that the coolant and/or oil that was leaking down from the LIM onto the lower driver's side and down the rear of the engine (below the EGR valve area) was due to leaking LIM gaskets.

But today I see that area is wet again! So it looks like maybe my rear head gasket is leaking? But how could coolant from a leaking head gasket travel upwards and also wet the top of the LIM? near the rear driver's side?

If it's the head gaskets, I don't think I want to do that work myself. Should I mayvbe try a coolant stop-leak product first?

What do you guys think?

Thanks.

Pictures of the area woudl help.

Is it leaking from the TB coolant ports?

Sorry, I don't know how to post photos yet...and I took a couple but you can't really see the wet areas in the photos because they're under other parts. I can email them to anyone who would care to see them.

As I noted earlier, I haven' refilled the coolant yet, and the engine hasn't been run since I did all of the work on Wednesday. All parts were dry when I reassembled everything. There was no coolant in the LIM or higher. So obviously there was no coolant in the throttle body ports (the throttle body wasn't even reinstalled at this point). And I don't think there could have been any coolant in the throttle body side of the supercharger. So I still don't understand how anything could be wet with coolant or oil. But maybe moving the water pump pulley while replacing the pump circulated a little coolant through the lower parts of the engine? I don't know.

Here's an update from today:

I attempted to remove the throttle body sensors in order to clean the throttle body. The screws on the other 2 sensors came out with no problems, as expected, but both of the screws on the IAC valve were a little tight. I slowly loosened them...and to my surprise the heads on both of them SNAPPED RIGHT OFF! Both screws snapped around 3 threads from the head. Amazing!
I was very relieved because I was able to swap that throttle body with one from a used supercharger that I bought a while ago just in case I would need parts.
I suspect that someone installed the longer screws (the ones from the TPS or the MAF) in the holes for the IAC valve, and that's why they were so tight.

Anyway, everything is back together now, but I didn't refill the coolant or connect the battery.

Tomorrow, before I do anything else I'll inspect the top of the LIM below the EGR valve area and also the vertical area along the rear driver side. I expect it to be dry nothing inside the engine has moved today. Then I'll refill the coolant and reconnect the battery and try to start it. Assuming I didn't mess anything up, it'll start and I'll run it and see if it's leaking on the rear driver side (or anywhere else).

If it remains dry, then I won't know what got it wet after I did the work on Wednesday.
But if there's a leak (and unfortunately I suspect that'll be the case) and it's a coolant leak from the rear head gasket, I'm thinking of trying some Bar's head gasket stop-leak that I bought today. I don't really want to have to try that, but the alternative of having a shop replace the head gaskets would be an expensive next step if the stop-leak doesn't work.
This stop-leak was the most expensive stuff at the auto parts store, and it says it contains carbon fibers and will safely and permanently seal leaks in head gaskets, etc. It also mixes with all coolant types and doesn't require a flush afterwards, just leave it in the coolant.

Just in case I'll need to take it somewhere for head gasket replacement, today I called a GM dealer and a small local private shop. The dealer wouldn't even give me a ballpark cost without seeing the car. All he said was that they need to diagnose it for $118.50 and go from there. The local private shop gave me an approximate estimate of $1,400 (including a valve job) and said it'd take 3 days, so I imagine that the GM dealer would charge a lot more than that. An awful lot more. Maybe I need to look into getting a low mileage used engine and have someone install it? I wouldn't even know who to call to make that happen.

I'll post an update tomorrow after I fill the coolant and run it.

Suggestions?

Update: Everything is back together, and the engine started right up and runs fine. I don't see any leaks anywhere, even the rear passenger side area that was wet the other day. So all of the work appears to be a success!

Note: I didn't replace the plugs, wires, or radiator hoses because the plugs were autolite double platinum 606 (I assume that's not the factory original plug so they were replaced at some point, the wires looked good and weren't delco so I assume they were already replaced at some point, and the radiator hoses looked good.

Thanks.