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We drove Bonnie up to Charlottesville yesterday and I noticed the engine temp running a touch higher than usual (210-220 vs 200) Cruising at 75mph had never brought that on before, so when we stopped for fuel I added some coolant to the overflow tank. I pulled out of the gas station and at the next light noticed wisps of white smoke coming from the exhaust accompanied by the strong smell of hot coolant. I immediately pulled into the next parking lot and shut the car off.

The oil level looked slightly high but not at all foamy. I could hear bubbling in the overflow tank but there were no visible leaks. I tried restarting once more but a very rough idle told me things were getting worse along with more white smoke.

I fear ahead gasket has let go at the least, or something cracked at the worst. I've never overheated the car so I like to think warping or cracking is out of the equation. All of the upper and lower intake gaskets were replaced when I did my major parts swapping a couple of years back. I'd like to feel like none of that stuff failed although it would be a cheaper alternative at this point.

I have dealt with constant code throwing for lean cylinder bank and low coolant temp ever since the hi-flow TB, 1.7 rockers, powerlog, 2.5 D/P and hi-flo cat. The engine has been smooth and powerful from the day I cranked it after the upgrades so I dismissed the code due to higher flows and lower cat temps.

Local shop is supposed to give me a price for repair sometime today but my gut says its going to be in the similar neighborhood of swapping to another engine...either way this isnt going to be easy on my wallet.

Even with the recently replaced parts I would still think UIM or LIM gaskets. Hopefully it doesn't hurt too bad!

crash93ssei wrote:Even with the recently replaced parts I would still think UIM or LIM gaskets. Hopefully it doesn't hurt too bad!

I agree with crash93ssei.

A compression test will most likely show no problem.

Something you might have done at the gas station was let the engine cool a few minutes and remove the radiator cap using a towel to protect if boilover occurred. I suspect your radiator was low hence it wasn't able to cool the coolant before the coolant was pulled back into the engine. So you got the higher stabile temperature.

I'd suspect a sleeved UIM and metal sleeved lower gaskets will do the trick. Be sure to inspect the lower intake for erosion in the gasket sealing areas.

He put on the sleeved UIM and metal LIM's a few years ago, I remember his build.

Sorry to hear it buddy! Hopefully it's nothing too expensive...

Wish you the best! Maybe the UIM failed anyways? Sometimes the sleeved ones can still fail after enough miles. It would be easy to check.

Been overloading on reading since last night about head gasket cost vs engine replacement. Trying to find a low mileage used engine is like hunting chicken teeth, which isnt surprising considering the model age. I noted from another thread the 05-up L26/L32 would be a bolt in swap with all my existing pieces bolting on with out mods. Taking advantage of the better engine for longevity would be desirable still depending on cost. This hit me a bad time money-wise (when doesnt it?) LOL

I would actually prefer it were the UIM/LIM that failed...I can take the hit to my pride on that vs another engine.

Well if you can find an L32, at least you'll have boost.

As it turns out the "heavy duty re-inforced" sleeved UIM manifold failed. Cracked at the EGR port and filling the LIM with coolant. He said it was smart I cut it off as soon as I did and prevented further damage. The car should be ready tomorrow but in the meantime I will be gathering parts for the L26 aluminum UIM swap. I know there has to be threads for this, so search mode is on but any chiming in will be welcome of course.
I'll be sticking with N/A but probably blocking off EGR and TB coolant passage...man what a pain, but glad its not head gaskets or worse!

Ok the L26 swap looks way more than simple bolt on...and blocking off the EGR seems to bring its own share of headaches as well.
What about blocking off the coolant port going thru the TB to prevent leakage from happening there again? I'm really put off the stovepipe UIM failed and I want more permanent fix for this issue.

Suggestions?

The L26 upper needs a TB adapter that I think ZZP sells. Because the L26 uses DBW. But other than that it shouldn't be difficult. I'm not sure about the coolant passages, so I'll let someone else chime in.

You can block off the coolant ports in the LIM. Drill, tap, and plug. Or you can RTV some dimes in the holes. That's what I did in mine. I'll never have a UIM failure again since the coolant can't even go past the LIM.

I was really worried when I read the title and saw the author. I was thinking an accident of some sort.

Glad to hear it was your UIM that failed and the repair (and cost) is better than your initial assumptions.

I will be interested in seeing how you block your coolant ports. Will be interested in doing this myself as I'm running the same UIM you were/are.

Also, how many miles on your car and since you replaced everything?

Hey sorry to hear that, it's a bummer I know!
I picked up an 04' L67 with 62,000 for $1,200.00 Shipped from Connecticut to Pennsylvania....super clean and still had Dexcool in it!! Lol. I still tore it down and got rid of the plastic gaskets before I dropped it in the car.
Good Luck!

nos4blood70 is correct.. tap it and plug it.. make sure the plugs are flush or counter sunk to keep a good seal, or have the holes tig welded shut and grind smooth. as for EGR you can block off a few ways... or unplug the egr and tune out the code. ZZP sells athe parts you will want for a alluminum intake setup IIRC. not that bad to do.

http://www.impalaforums.com/diy-do-it-y ... ngine.html
http://www.pontiacbonnevilleclub.com/fo ... c4181.html

I found the L26 manifold for a good price and the TB adapter doesnt sound bad but the fuel rails are the real issue...those puppies are pricey! I may just go with plugging holes in the LIM. I still have the stock LIM I swapped in favor of the ported one on the car now. I could take that one to a welding shop and have the holes either tapped or welded shut (I dont have taps, but might know someone who can, hmmm)

I did the whole upper gasket build at around 103k mi and the car now has almost 140k...so not such impressive figures for the "better" plastic intake...and I note once again...the car has never overheated once while I've owned it.

Bill Wren plugged my TB ports a long time ago. Here is a picture:




More images in this thread:
http://www.pontiacbonnevilleclub.com/fo ... 24890.html

Things just keep heading downhill. While I was curious how anti-freeze could have screwed up a cam position sensor and an ignition module I'm not certain but both of those had to be replaced. Now I am experiencing this cruising speed/light load/ignition miss problem. I read several threads on this chronic issue and given that plugs/cam sensor/IM have already been swapped, I guess my Summit coils are now suspect? Or is it possible that coolant caused a short that has spawned these problems? Could crank sensor also be culprit? Or maybe its just bad luck they came so close together?
I continually get the low coolant temp and lean condition codes, but I've been getting those ever since the build project over a year ago...given the 180 t-stat, P-log,1:7 rockers and 2.5 DP w/hi-flow cat.

So after coils, I'm kinda stumped, and honestly, if my brother asks about buying the car again, I'm thinking strongly about letting it go. There is nothing I hate worse that a bug-ridden car I cant trust for a long trip. I'm good with fixing problems, but I despise have to fix the same thing multiple times. (without generous miles in between)

I will say, when I bought summit coils a few years ago they were rebranded accels and you know our cars HATE accel

It's weird too that you car is complaining about the 180 stat. How are the fans set on your tune?