Radiator / Coolant Leaks

Replaced plugs and fired it up. No leaks. i was told this is a 16 hour job at the dealer. Wrench also told me the bill would have been around $2500-$3000. It cost me 240 for the cover, 20 for the gaskets, 50 for the water pump and a couple of lunches for the people that helped. NEVER AGAIN

96riv wrote:

Replaced plugs and fired it up. No leaks. i was told this is a 16 hour job at the dealer. Wrench also told me the bill would have been around $2500-$3000. It cost me 240 for the cover, 20 for the gaskets, 50 for the water pump and a couple of lunches for the people that helped. NEVER AGAIN

Congrats. I can't stand overpaying for mechanical work that I can never really trust fully.

I just flushed out my original DEX COOL , although it looked clear there was corrosion on the water neck under the hose clamp, I will download the vid soon.

49,000 miles and 12 years, this stuff is supposed to last 5 yrs/150,000
I guess its my fault .

Hi all... what a great forum... thanks for keeping this info alive on these great cars.

My 95 (supercharged) is loosing coolant (about 2-3 quarts p/1000 miles). Sometimes, when I start the car after it is warmed up and sits for about 30 - 90 minutes, the engine wont idle well and has to be revved up slowly before it starts running properly. I dont see any white smoke. The car starts and runs perfectly when cold.

I changed the air cleaner and that definitely helped the issue but I noticed it slowly coming back today. Im thinking maybe I have a intake leak and was wondering if I have to pull both heads to renew the intake gasket and what other maintenance items i should do while the parts are off. I recently had a mechanic install a new pressure regulator to solve a rough idle issue. The car needs to have new plugs/wires installed which I will be doing soon.

The car has 140K and runs very well after started.

Thanks in advance for the help!

Jeff Del Vecchio - Pittsburgh, PA

another pittsburgh riv. nice. where in pgh u from?
i had a similar coolant issue and it was my water pump.

I live in monroeville but Im moving to Oregon at the end of the month... Im hoping the riv will make it wothout an issue... I think she will without any problem... I drive her for my job and put about 800 miles a week on her.

great cars...

jeffyd123 wrote:

My 95 (supercharged) is loosing coolant (about 2-3 quarts p/1000 miles). Sometimes, when I start the car after it is warmed up and sits for about 30 - 90 minutes, the engine wont idle well and has to be revved up slowly before it starts running properly. I dont see any white smoke. The car starts and runs perfectly when cold.

I changed the air cleaner and that definitely helped the issue but I noticed it slowly coming back today. Im thinking maybe I have a intake leak and was wondering if I have to pull both heads to renew the intake gasket and what other maintenance items i should do while the parts are off. I recently had a mechanic install a new pressure regulator to solve a rough idle issue. The car needs to have new plugs/wires installed which I will be doing soon.

The car has 140K and runs very well after started.

Thanks in advance for the help!
Jeff Del Vecchio - Pittsburgh, PA

Jeff,
Replacing the Lower Intake Manifold (LIM) gasket on these does not require removal of the heads.
The LIM gaskets are notorious for failing and allowing coolant to be ingested into the engine or you may even see coolant coming out of the rear cylinder head on the passenger side area. Visible from under the car with a flashlight.
Your supercharged engine is designed with the LIM being bolted to the heads and then the Supercharger being bolted to the top of the LIM.
I don't know how much mechanical experience you have or the time to do the job, but if you suspect the LIM is leaking, again very common on 3800 engines with your mileage, then I would recommend getting it replaced before driving to Oregon.
Things could get catastrophic on the trip if this goes from the current volume of leak to a major one, 2 to 3 quarts every 1,000 miles is a lot of fluid to be loosing.
Hopefully it's leaking externally and not into the engine as coolant does not make for a good lubricant and WILL cause premature engine failure.

First, you need to have a cooling system pressure test performed and find out where the coolant is going, at a bare minimum.

What does the oil look like on the dipstick, is it a coffee / milkshake kind of color.? Also remove the oil fill cap from the front valve cover and turn it over, what do you see there, any foamy coffee color stuff. If so your coolant is going INTO the engine and as you know by now that is not good news.
Do a search on here and look for "LIM" as a key word and look in the "Write Up" section there should be some more detailed info for you to read regarding doing this job.
But don't drive 3,000 + miles if you think you have a LIM gaskets leaking. My bet is you wouldn't make it.

Welcome to the site and don't hesitate to ask questions.
I don't want to sound like Mr. Doom and Gloom but I would hate to see you have major engine problems on this upcoming trip. If the motor were to seize up in mid trip what could you do then.
Rick

Where in Oregon?? I had a guy ask if mine was new and at what car dealer. Apparently, not many Rivs to be found in these parts.

ohh nice jeff. im in forest hills.

Scotty, you need to get your toolbox together and get over to Jeff's and replace his LIM Gasket for him before the end of the month, when he try's to drive to Oregon.

Or should I have said Tackle-box.???

Rickw -

Thanks for the great advice and good news that I don't have to pull the heads. I may do it before I leave and I will get the pressure check done ASAP. The oil looks normal coffee color after 1,000 mils or so. I run Mobil 1 hi mileage 10/30.

I will read up on the write-up and get ready. I assume its about a 6 hour job? I have the expertise to do the job if needed.



Playa - Moving to Bend, OR. True about no rivs there... All you see in Bend is Subarus since they don't salt or even plow in the winter... just a sprinkle of cinders and you're on your own LOL.

thank you very much guys!

Jeff

Jeff,
Make sure you get brand name gaskets, such as Fel-Pro or OEM GM stuff if available and make sure the LIM gasket is Aluminum.
The earlier gaskets weren't Alum and are the ones prone to failure.
Yes, give yourself the day to it if you've never done one before. That will also allow time to run back and forth to the parts store for anything you may have forgotten.
Glad to hear your capable of doing it yourself, otherwise the shops get a lot do do this job.

lol i know u know that i dont even know how to change my own oil. let alone an LIM gasket lol

xxsupergman25xx wrote:

lol i know u know that i dont even know how to change my own oil. let alone an LIM gasket lol

that's why he said 'tackle box'

Albertj

Hi Guys... thanks for all the advice...much appreciated!!


OK... I did the coolant pressure test and all is well in that department...There is some brown fluid under the supercharger on the back of the manifold but i think its just a small oil leak and I didn't see any coolant. I don't know where the coolant is leaking from but I'm going to be looking at the water pump next.

There is no coolant or foamy stuff on the oil cap. Im fairly confident that no coolant is getting in the engine.

The car is starting better but still has a small hesitation when starting warm.

It has been having a problem with an intermittent and rare (about every 8 hours or so) hard miss when climbing hills under light acceleration...Which suddenly got much worse yesterday when I drove back from Ohio. the miss was happening much more consistently...kinda like the engine was being turned off for a split-second and/or shuddering. The SES light came on while i was driving which is rare. It only happens when at highway speeds and usually when I'm in overdrive. Ive tried moving the accelerator up and down a bit to reproduce the miss but it doesn't seem to make it happen (checking the throttle position sensor)

I'm going to take it to advance auto to get the codes read although I'm pretty sure it will say its a misfire. I was reading on the forum that it could be the EGR valve. I just replaced the plugs an plug wires which on Tuesday was suddenly causing a very bad cross-firing issue (solved that). and Im going to look at the coils to see if they are dirty or have bad contacts.

I'm wondering if the throttle position sensor or crank position sensor could cause any problem like this?

Any ideas would be great... By the Way... my old plugs where in perfect condition... light brown and still gapped at .56 so the engine internals seem to be fine.

thanks guys!

Jeff

The miss sure sounds like a misfire. New spark plug wires will do well for you in this situation.

The coolant stuff - I'm not positive about the Series I 3800s, but if they used similar LIM gaskets like the Series II (Plastic) it may be time to replace them. The plastic LIM gaskets disintegreate over time and then you start ingesting coolant into the cylinders or just have a coolant leak... Also on the Series II there is a plastic elbow that runs from the alternator tensioner to the lower intake - this is a coolant elbow and they get brittle and crack after many years.

A couple things to look for. Again, my experience is with the Series II 3800s, the 95 SC is Series I but there are a lot of similarities.

thanks deekster...

I just did the plug wires. Im wondering (after some reading) if the plug wires could be causing electrical leakage into the wiring harness that lays on top of the manifold...Hmmm I did put looms on them and may have to get under there again to make sure they are far enough away. My mechanic sold me some plug wires (no name brand) and I'm thinking of replacing them with AC Delco wires

On the coolant issue... I did replace that nipple fitting that comes out of the manifold (under the SC). It was almost cracked in half. I found a nice steel one in the "HELP!" section at advance auto. I have a series I so the nipple is different than what you have I think.

After another 2 hours of reading on this awesome forum I am going to tear into the coils... I have a sneaking suspicion that one of my coils is heating up after driving for a while and intermittently failing.

thanks

Jeff

I'd say that you are on the right track.

Good call on fixing that coolant "nipple". When I did my LIM gaskets I found mine was cracked in half and i had to get creative to get the broken threads out. (for you series 2 guys, this nipple is the equivalent of your plastic elbow under the SC snout)

Also, the series one is not as prone to LIM gasket failure as the series 2. For whatever reason the design is slightly different, and they didn't have the dexcool from factory breaking them down. That said, its always good to do a replacement for piece of mind, especially with a higher mileage engine, that sees boost often. Also as a side note, there are no metal framed LIM gaskets available for the series 1 sc.

jeffyd123 wrote:

Hi Guys... thanks for all the advice...much appreciated!!


OK... I did the coolant pressure test and all is well in that department...There is some brown fluid under the supercharger on the back of the manifold but i think its just a small oil leak and I didn't see any coolant. I don't know where the coolant is leaking from but I'm going to be looking at the water pump next.

There is no coolant or foamy stuff on the oil cap. Im fairly confident that no coolant is getting in the engine.

The car is starting better but still has a small hesitation when starting warm.

It has been having a problem with an intermittent and rare (about every 8 hours or so) hard miss when climbing hills under light acceleration...Which suddenly got much worse yesterday when I drove back from Ohio. the miss was happening much more consistently...kinda like the engine was being turned off for a split-second and/or shuddering. The SES light came on while i was driving which is rare. It only happens when at highway speeds and usually when I'm in overdrive. Ive tried moving the accelerator up and down a bit to reproduce the miss but it doesn't seem to make it happen (checking the throttle position sensor)

I'm going to take it to advance auto to get the codes read although I'm pretty sure it will say its a misfire. I was reading on the forum that it could be the EGR valve. I just replaced the plugs an plug wires which on Tuesday was suddenly causing a very bad cross-firing issue (solved that). and Im going to look at the coils to see if they are dirty or have bad contacts.

I'm wondering if the throttle position sensor or crank position sensor could cause any problem like this?

Any ideas would be great... By the Way... my old plugs where in perfect condition... light brown and still gapped at .56 so the engine internals seem to be fine.

thanks guys!

Jeff

Warm run problem *could * be crank sensor but I am not sure how likely. They go "bad warm."

Autozone can read the codes, but a dealer's Tech II can read the sensors while running. There are some other scanners that can as well (I don't recall exactly but Snap-On comes to mind) - you can get a copy of Alex Peper's "Car Code" adn a dongle, that will read the sensors while running and take a log. I have used that to diagnose running problems, it's pretty effective. Might save some time in diagnosis to look at logs not just codes. I don't know if there is a GM dealer closer to you than #1 Cochran in Monroeville. It also is highly likely that an independent mecahnic around you has a Tech II that will do the job. I was surprised once in Pittsburgh - i had a plug wire go bad and it took out a coil. I did not know what was wrong except the car was running crappy. Took it to the FIrestone in Pleasant Hills. Surprise surprise... they had five GM Certified technicians, 3 of whom were in that Sunday; and a factory scanner (And a good attitude). They found the problem, got me a replacement coil (it is still on the car 100K later) and scavenged a wire n/c from "shop supplies" (they had replaced all wires on a Bonneville & kept the good ones) saying "be sure to replace them soon, when one goes the rest tend to follow."

Point is if you call around and ask some of the independents if they have diagnostic scanners - most of the larger ones at least around you in Pittsburgh probably will. The chains (Firestone, Goodyear/Gemini) in my experience vary in quality from location to location BUT there are some very good ones and they are not that hard to find.

And if you happen to come across a working Tech II that you can buy for less than a grand, and you have the $$, consider doing so.

Albertj

Karma.. thanks for the info on the LIM gasket... I had broken plastic in the threads too. gotta be careful removing all of them. My Tstat went crazy for about a week after I changed it... car wouldn't warm up!.

Albertj... I was reading that most of the advance auto scanners wont read the OBD1.5 codes... I'll check Autozone... I plan on going down there today (the one near McKeesport) and I think Im going to just buy 3 of the coils as mine are stock.

It appears that alex peppers site is for OBD II only so it wont work on my dinosaur.

I do have 2 questions though...

1 - Doesn't a coil just completely fail as opposed to an intermittent failure? In my experience I've seen them just stop working but that was many years ago on an old 62 dodge powerwagon.

2 - could the base that the coil attach to go bad? would that be a more likely cause of an intermittent failure than coils?

thanks again guys

Jeff

When you have had the cooling system open you have to bleed the air out of the thermostat housing - that's what the little screw is on top of the thermostat. That's probably why your temps were going crazy.

Coils rarely fail. Not to say they don't, but when I was selling parts it was the number one attempted to return electronic part. Anytime somebody asked me for a coil, I would steer them elsewhere first. On 3800s I have yet to personally experience a bad coil, and I've worked on about 25.

The base of the coils is the ignition module.

ahhhhh, I did not bleed the system. That was probably it. I thought I cleaned out those broken threads really well. maybe that is where i saw my fluid disappearing to as well. Hmmmmm

That is good info on the coils... I noticed autozone doesn't have any warranty on theirs.

Im not sure what to do here... I dont want to waste $90 on three cheapo coils (the AC Delco ones are about $50 each) The ignition module is about $140. Im leaning towards the ignition module heating up and intermittently failing.
The Engine Control Module (under the drivers side hood) has been replaced by the previous owner BTW.

any info would help

Im going to go in the garage and pull it out and see if its making good electrical contact and just inspect it.

thanks deekster...great info.

that car of yours sounds pretty awesome from the look of your sig.

Jeff

Do you have an ohmmeter.?
That will allow you to test the primary and secondary windings inside the coil.
Now that will give you an indication of the health of the coils when cold. In rare circumstances a coil can fail when heatsoaked and then test good after cooling down.
But I would test the resistance as I mentioned before condemning a coil.
What you may want to do, which is highly recommended for preventive maintenance as well, is to remove each coil, clean the electric contacts and the base of the coil.
Then also clean, with scotch brite pad, fine sandpaper or wire brush the top surface of the Ignition Control Module (ICM) which is the unit the coils are bolted to. Also remove the ICM from the steel mount and clean the bottom side of it as well.
Before trying to remove the ICM remove the harness that is attached to the front of it with one small bolt and then remove ICM and clean it up. Inspect all the pins inside this connector block on both the harness side and the ICM for any corrosion or bent pins.
It is a known source of corrosion (Top and Bottom) and that alone can cause problems.
If you have Dielectric grease, apply a thin coat to both top and bottom surfaces to protect it from future corrosion.
Also clean the 2 electrical (male spade) connectors on each coil and apply a small amount of dielectric grease to those as well before assembly.
While you have the ICM loose from the mount you should remove the black ground wire that goes from the ICM to a bolt / stud on the engine (you can't miss it) and use some fine sandpaper to clean the ring terminal and inspect it for broken or frayed wires.

thats a great idea aficiando...thanks

I have some questions...

1 - What ohms on what leads should I test? or should I just look for consistency between the three coils? I would still need to know what leads to test

2 - Do I need to discharge the coil? I hate shocks! LOL

3 - do you happen to know what kind of bolt head is on that harness? I'm wondering if its some sort of torx or just an allen head?

4 - when applying thin film of dielectric grease to the ICM did you mean put the grease on the contacts or on the housing to seal it?

I did pull one of the coils off and it looked pretty clean under there but I will start cleaning everything immediately.

thanks so much you guys are really great.

Jeff