PontiacBonnevilleClub.com

what can a UIM LIM cost at a avg mechanic ?

$700-$1000, depending on your mindset for parts replacement, assuming he is providing parts.

EDIT: Parts can average $200-$300, and it isn't all that bad to do, assuming you can be organized and know what you are looking at. Make sure you get the right parts though, because not all new parts address the common issues like others do.

RJolly87 wrote:$700-$1000, depending on your mindset for parts replacement, assuming he is providing parts.

EDIT: Parts can average $200-$300, and it isn't all that bad to do, assuming you can be organized and know what you are looking at. Make sure you get the right parts though, because not all new parts address the common issues like others do.

well what parts do most people recommend, assuming i have no blown head gasket as this guy mentioned

and is it worth it on a car with 167k miles and other various things i need to fix still ...

or just try and sell it as those GXPS always looked nice with the V8

When I did mine, I carried the mindset of working on an engine that has seen 20 years and 175k miles of service. If there was a chance it could fail in the future, or is getting aged after said period of time, it got replaced. Examples such as injector o-rings, valve cover gaskets, fuel rail o-rings, etc. I only wanted to do this job 1 time. It was a bunch of "since it's this far apart anyway, let's swap this while we're in here".

It may be wise to lay the cards on the table, to look at what else needs to be fixed. If your engine has been lubricated by chocolate milkshake for god knows how long, it may be a more cost effective move to have it slapped back together, and then dump the car. If the odds and ends are not that big of a deal, and the engine oil has never been molested by coolant, there is a different set of factors.

As long as maintenance has been kept up and problem areas addressed, the 3800 has a reputation of running until it drops dead. When it dies, it is usually nothing short of spectacular, leaving no doubt in your mind it's dead, having covered hundreds of thousands of miles in the process.

GXP's are nice and everything, but the engines use more fuel, and don't share the longevity that the 3800 does. Accessibility is also a real concern for repairs.

Most suggest doing manifold gasket jobs yourself however, because it is such a pricey repair.

I replaced the fuel O-rings and put in a new fuel pressure regulator & new valve cover gaskets. FWIW, there'll never be a better or more unobstructed opportunity to change the upstream oxygen sensor IMO. (heater hoses too) Good luck.

so i rented a OEM block tester [ fluid tester for radiator] and the test fluid i had never changed to yellow? so either im doing it wrong and oxygen is getting in which i read will change fluid back to blue or mr shady mechanic was lying?
-watched a video about blown head gaskets and the guy goes over various tests,and the milky oil isnt a reliable one,only two compression and the fluid test[ below]

http://www.amazon.com/OEM-Tools-27145-O ... B004FELK6A

there is also a double chambered version but cant find it to rent.said to weed out false positives.

also sprayed mist water on the ICM while engine running at night no sparks to indicate rusty loose wire or such, maybe another area to test?

car does seem like its having a harder time turning over while cranking and other times cranks then goes silent then cranks up and starts its odd. any ideas?

This could be an indication that the engine is ingesting coolant. If it is ingesting coolant, it should be fixed quickly because there is a danger of hydrolock, which can result in a dead engine.

RJolly87 wrote:This could be an indication that the engine is ingesting coolant. If it is ingesting coolant, it should be fixed quickly because there is a danger of hydrolock, which can result in a dead engine.

what is a indication? my uncle had this happen with his 96 bonneville

what about the headgasket test i did

blinky99 wrote:also sprayed mist water on the ICM while engine running at night no sparks to indicate rusty loose wire or such, maybe another area to test?

car does seem like its having a harder time turning over while cranking and other times cranks then goes silent then cranks up and starts its odd. any ideas?

I advised you to mist the spark plug wires not the ICM.
Spark plug wires--anywhere on the wire itself including the ends--very often arc to metal as they age.
The only visible indication is a small white spot on the spark plug wire where the arcing has taken place.
The ICM will never arc sparks but the coils on top of it can.

As for whether or not you did the test wrong--why don't you re-read the directions and repeat the test?
That way you can be more confident in your testing.

Read the articles I located and linked for you a few paragraphs below, to gain an understanding of intake manifold gasket problems and head gasket problems.

blinky99 wrote: what is a indication? my uncle had this happen with his 96 bonneville what about the headgasket test i did

The starting issue is an indication of coolant in the cylinders most likely from the intake gaskets leaking.

What about the headgasket test you did?
Everyone here has told you that your mechanic is most likely wrong.
Whether it is simply ignorance of a very well known issue or an intentional deception, who knows?
I wouldn't be very happy with either of those.

In case you haven't understood it, when the intake manifold gaskets on 3.8L GM engines go bad they leak coolant into the cylinders.
Unlike many other engines, the GM 3.8 liter engines have coolant passages in the intake manifolds.
Mechanics who are ignorant of this fact will assume that coolant in one or more cylinders indicates a blown head gasket.

If you read these 2 articles, you should gain a much clearer understanding https://www.yourmechanic.com/article/sy ... ld-gaskets
and this one http://www.agcoauto.com/content/news/p2_articleid/200
As has already been said, head gasket problems, in the absence of severe overheating are extremely rare on the GM 3.8 liter engines.

Who knows which tests your mechanic has or hasn't done?
For all we know, he found coolant in a cylinder and assumed that the head gasket is bad---which is far less likely than bad intake manifold gaskets.
Head gaskets, in the absence of overheating, are the least likely possibility.
The only way to absolutely rule out a headgasket is to perform all of the tests listed in the link I posted.

It would be very easy for a mechanic to get away with doing an unnecessary head gasket job, since the intake gaskets have to be removed and replaced in order to change the head gaskets.

If it makes you happiest to have this mechanic do the head gaskets, then go right ahead.
We have all recommended that you get the car fixed before disaster strikes.

If a family member or friend who knows about cars has a mechanic whom they have found is knowledgeable and trustworthy, then you might want to get that mechanic's opinion.

In case you think that I am somehow "anti-mechanic" , then you may be interested to know that I used to be an automotive mechanic.
Mechanics are good and bad, honest and dishonest, competent and incompetent, just as you will find in any profession.

he said he did the fluid test for combustion gases which he said was positive color change,and the compression test which lead to #2 cylinder being low compression. he ran my codes which had misfire in them and checked for electric misfire gas and coolant related misfire which coolant was positive which he said lead him to the fluid and compression tests for blown head gasket. Was a bit ago so im sure im missing some info. He said i had one and i cant replicate a positive test.

-I've seen youtube videos of the fluid test and it turns yellow for them even with engine cold. So the test seems fail proof. Ive followed instructions from the block tester and it never goes yellow like in videos. My dad also has photos of the fluid test he did from way back on his car we are using as a positive headgasket blown car, and my testing fluid never changes to the color he has photos of. Ill upload the fluid photos i took

i've done the fluid test on my dads car which has a known gasket and the fluid i bought from NAPPA only slightly turned to green not bold yellow like in videos i've seen. I dont want to do the gaskets not worth it rather just buy a new car with all the other things i need to fix on this one.

But id like to know for sure so far my testing is negative,also negative for any signs of over heating or. Next is to do the compression test and rent the tool and findout how to do it to see if i get same results of low compression.

again ty.
-again i dont trust this mechanic owner anymore,but the mechanics who work under him are the same that have been there for 5 years or so i do trust, i should get their opinion and watch them do the testing with the fluid i bought.

I can understand why you'd rather just replace the car.
The gaskets are an expensive repair, though the engines are very sturdy, aside from the intake manifold gaskets.
The replacement gaskets are aluminum and do not have the same troubles.
Be aware that this intake gasket issue was not limited to Bonnevilles.
All 3.8 liter engines from around 1995-on.
It is also not limited to the 3800/3.8 liter engines and Ford and Chrysler made cars with the intake gasket failures, too.
http://www.enginebuildermag.com/2010/07 ... d-gaskets/
Search online before buying another car to find out what problems frequently occur with whatever model catches your eye and fits your wallet.
Ideally, find a forum like this one, where people are very familiar with the typical problems that a certain car develops.
For compression testing, videos by some mechanics on Youtube can be helpful http://www.ericthecarguy.com/the-basics ... ssion-test

i thought it was bonneville specific due to dexcool, i never found out what type of coolant should i add? and because of the funnel on the radiator cap i cant see the level, aside from it being at the cold fill line in over flow tank.

maybe keep it and tinker with it myself see what i can learn or just drive it until it dies.

- Id just like to know if it is a head gasket before i put money into brakes, one more tire, and whatever is causing a shudder when i break at 30-40mph, but if i turn the wheel slightly while breaking can make the shudder stop, been like this couple months.

tie rod wheel bearings perhaps?

AC doesn't work either due to a large leak as i cant even get it to fill after two cans of refrigerant

also with the starting issues at time,and seems to have a hard time turning over at times,not sure what to think
Ill try misting the wires, but i misted the whole area and got nothing.

When the system has Dexcool in it, then all you can add is Dexcool.
With a flashlight, you should be able to see in there, despite the funky funnel.
If you want to rule out a headgasket problem, then follow the instructions here http://troubleshootmyvehicle.com/gm/3.8 ... d-gasket-1

If you're willing to spend a weekend working on your car, the complete instructions on replacing the intake manifold gaskets are here
http://www.pontiacbonnevilleclub.com/fo ... c3591.html
It is time-consuming but not difficult if you are reasonably handy with a wrench.
It is a job that requires a torque wrench, just like any engine repair.

The shaking could be a warped rotor, bad tie rod end or something else.
You can always get a free front end check at an auto chain store and do the work yourself.

MKMike wrote:...If you're willing to spend a weekend working on your car, the complete instructions on replacing the intake manifold gaskets are here
http://www.pontiacbonnevilleclub.com/fo ... c3591.html
It is time-consuming but not difficult if you are reasonably handy with a wrench.
It is a job that requires a torque wrench, just like any engine repair...

Also I have prepared an Excel spreadsheet that details the process step-by-step to the most minute detail, with all torque values and most wrench/socket sizes filled in, when and where to use what lubes/sealants/threadlockers, etc. If you get that far, LMK and I can email it to you.

(I've done this procedure on way too many 3800's!)

so today started car, heard a loud pop then lot of black smoke from engine bay, turned car off went to look for source couldn't see, smelled like burning rubber/

restarted car started fine... would consider this from a cold start

Clogged air filter
Wrong grade of fuel
Incorrect timing
Engine overheating
Faulty injection system

this seem to popup with google searches also to rich of a combustion/fuel ratio condition?

Bad fuel pressure regulators were recalled on the 2000 engines without a supercharger .
They caused backfiring upon startup---sometimes causing the plenum (upper intake) to explode and could set things on fire.
If you input your VIN here, you can find out if it was replaced or not https://my.chevrolet.com/recalls
RECALL SUMMARY:
ON CERTAIN PASSENGER VEHICLES EQUIPPED WITH 3800 V6 (L36) ENGINES AND CERTAIN DELPHI FUEL PRESSURE REGULATORS, THE REGULATORS HAVE A MUCH HIGHER THAN USUAL RATE OF FUEL LEAKS. A LEAK CAN ALLOW FUEL TO ENTER THE INTAKE MANIFOLD THROUGH A VACUUM LINE. IF THE ENGINE DOES NOT START WHEN CRANKED, THE FUEL FROM THE LEAKING REGULATOR AND A MISTIMED SPARK CAN CAUSE A BACKFIRE.
CONSEQUENCE:
THE BACKFIRE CAN RUPTURE THE INTAKE MANIFOLD. THE RUPTURE OF THE INTAKE MANIFOLD CAN DISPLACE A FUEL LINE, PULLING AN INJECTOR OUT OF PLACE, AND CAUSING A FUEL LEAK AND POSSIBLE FIRE.

great info ty
, this has happened about 3 times now but this has been the most smoke i've see, so this is for sure what is happening?

website says this
"Currently, there are no recalls or programs associated with your 2000 Pontiac Bonneville

VIN: xxxxx"

It may be that the fuel pressure regulator has failed, even if it had been replaced after the recall.

Simple tests to do.
Carefully pull the vacuum tee off the fuel pressure regular and smell it (not a joke).
If it has any gasoline smell or if there is any liquid present, even just a drop, the FPR is bad. No need for any further testing.
The only thing that should be in the vacuum lines is air.

Another test, if you are going to start the car anyway, disconnect and plug the vacuum tee at the FPR.
Run the car this way for several minutes. If you see any fuel come out of it, it is bad.
The fuel pressure regulator is mounted in the fuel rail, on the radiator side of the supercharger towards the belt end.

would the FPR be responsible forthe trouble starting at times?

blinky99 wrote:would the FPR be responsible forthe trouble starting at times?

It can be but plenty of things can cause hard starting. Even intake manifold gasket issues can do that.

" An internally leaking regulator can cause long crank times as it takes the pump longer to build pressure in the system. "
taken from here: http://performancefuelsystems.com/tech- ... ntest.html
Here's a video by a knowledgeable mechanic
https://www.youtube.com/watch?v=AKtR_yF7bi8