97 PA mysterious coolant loss

[fishinfool56]

Just replacing upper and lower gaskets only. I bought the fel- pro upper and lower set. I believe the lower was ms98014T the picture shows them as the metal ones. I haven't straight edged the lower intake as of yet. Gonna a do that tomorrow while waiting on Amazon. The plenum is plastic. Im pretty sure that when I saw the pressure dropp while running I tried to pump it back up. In doing so I basically marched myself into the good ol po300 code, and an increase in temperature, then a no start condition lol. When I tear something up I usually tear it up good lol. Im hoping to have the gaskets and finish tomorrow. Then I gotta drive it a bit to get the readiness monitors reset so I can get through Delaware dmv.

so to be clear you are replacing the lower intake manifold and the gaskets with the upgraded metal ones (between the lower and engine), i believe the ones between the lower and upper manifold may be metal but not sure, ive not done the job on a L36 before. @HotZ28 would know. Theres a chance your dorman manifold isnt flat. can you take a straight edge and confirm its flat around the important spots? The cooling system dropping to 4lb when running could have been a factor of your water pump rotating things and I wouldnt read into that unless you pumped it up after it was running and you were unable to keep it up with the tester. There could have been air pocket basically that just relieved the pressure to 4lbs.

Did you buy gm gaskets

 

[BuickGirlFromMars]

Just replacing upper and lower gaskets only. I bought the fel- pro upper and lower set. I believe the lower was ms98014T the picture shows them as the metal ones. I haven't straight edged the lower intake as of yet. Gonna a do that tomorrow while waiting on Amazon. The plenum is plastic. Im pretty sure that when I saw the pressure dropp while running I tried to pump it back up. In doing so I basically marched myself into the good ol po300 code, and an increase in temperature, then a no start condition lol. When I tear something up I usually tear it up good lol. Im hoping to have the gaskets and finish tomorrow. Then I gotta drive it a bit to get the readiness monitors reset so I can get through Delaware dmv.

If you have the engine torn down to the LIM, I highly suggest waiting more time and buying the proper metal GM gaskets to replace them. If you can, find a part number on your intake or find anything to indicate who made it , because the proper repair is to replace both the lower intake and the upper. But Im sure many people just do the upper. The upper already has been done once as you noticed. The area in question is around the stove pipe. I cant tell from the pic if you have the original lower or not, but could you include a picture of the same area on your dorman intake? ATP and gm intakes are better quality if you find an issue, fyi.
The stovepipe that goes into the intake there in one of those holes, can you measure its diameter and take a picture of it too?

 

[BuickGirlFromMars]

89017272 upper intake from GM, only 150$ USD.​

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[fishinfool56]

If you have the engine torn down to the LIM, I highly suggest waiting more time and buying the proper metal GM gaskets to replace them. If you can, find a part number on your intake or find anything to indicate who made it , because the proper repair is to replace both the lower intake and the upper. But Im sure many people just do the upper. The upper already has been done once as you noticed. The area in question is around the stove pipe. I cant tell from the pic if you have the original lower or not, but could you include a picture of the same area on your dorman intake? ATP and gm intakes are better quality if you find an issue, fyi.
The stovepipe that goes into the intake there in one of those holes, can you measure its diameter and take a picture of it too?

Sure, I'll grab some pics tomorrow morning and post up. Hopefully I can find my dial calipers,

 

[BuickGirlFromMars]

Sure, I'll grab some pics tomorrow morning and post up. Hopefully I can find my dial calipers,

Even a small ruler may work for this purpose, I just know the revised one is smaller than the OEM(not sure what that diameter was tho)Evidently GM doesnt sell the lower intake atm anymore, maybe in the future but not now.
here is what it would look like. I also never realized before the lower intake is where the thermostat sat, but im sure id of figured it out. I have a way to find out if yours is OEM or not. Can you show me your thermostat housing, take a side shot and a picture inside the opening towards the intake.
Then, can you take a picture of your lower intake at the thermostat landing. A couple high res ones if you can.
The thermostat provision will tell us if you have the original 1997 Intake or if you have the newer one. (To use the newer one you should also buy a newer thermostat housing as well)

 

[fishinfool56]

Even a small ruler may work for this purpose, I just know the revised one is smaller than the OEM(not sure what that diameter was tho)Evidently GM doesnt sell the lower intake atm anymore, maybe in the future but not now.View attachment 47718
here is what it would look like. I also never realized before the lower intake is where the thermostat sat, but im sure id of figured it out. I have a way to find out if yours is OEM or not. Can you show me your thermostat housing, take a side shot and a picture inside the opening towards the intake.
Then, can you take a picture of your lower intake at the thermostat landing. A couple high res ones if you can.
The thermostat provision will tell us if you have the original 1997 Intake or if you have the newer one. (To use the newer one you should also buy a newer thermostat housing as well)

 

[fishinfool56]

The stove pipe stayed in the plenum. It was kinda loose in the hole, I was reading that the one with the Dorman replacement plenum is slightly smaller than factory. The small rectangle 2 bolt plate should allow me to access the coolant passage in the intake to retrieve the broken piece of the elbow that fell in correct? Hopefully today the blue bus shows up and I get the lower gasket set. My plan is to pipe dope the lower bolts and loctite the upper bolts.

 

[BuickGirlFromMars]

The stove pipe stayed in the plenum. It was kinda loose in the hole, I was reading that the one with the Dorman replacement plenum is slightly smaller than factory. The small rectangle 2 bolt plate should allow me to access the coolant passage in the intake to retrieve the broken piece of the elbow that fell in correct? Hopefully today the blue bus shows up and I get the lower gasket set. My plan is to pipe dope the lower bolts and loctite the upper bolts.

only use thread sealant or loctite to seal bolts in the coolant. pipe dope isnt meant for auto.

Also, your lower intake Is OEM, which is less desireable. I would personally seek a newer intake, but theres a chance that may require a new tensioner bracket, your car uses a single metal elbow and a plastic one nearby, the new intake would be 2 plastic (which can be made metal)

But I dont recall if the new intake can be used with the original bracket where that pipe goes into or not , but just throwing that out there.

 

[fishinfool56]

Looks like I'm dead in the water. The "stove pipe" melted the plenum. Have to order one of them now. It had the Dorman replacement intake on it, so much for it fixing the known issue.

 

[fishinfool56]

So i completed the job of both intake gaskets tonight. I replaced the lower with the fel pro aluminum, and ended up buying a new dorman plenum with gaskets included. Put everything back together and it still won't run. Every electrical plug is where it belongs, vacuum line in place ect. I pulled the plugs dried them off and even cranked the motor with the plugs removed to clear any oil/coolant that may have been in the cylinders. Put the plugs back, in they were replaced a few months before this all started. It will crank like a champ but will not fire. I'm at a loss of what to look for. Everything seems to be correct but I missed something somewhere. Is there a relearn process or anything that commonly gets missed when this job is done?

 

[HotZ28]

Are the plugs firing, or are they still contaminated with coolant from the previous failure?

 

[fishinfool56]

Are the plugs firing, or are they still contaminated with coolant from the previous failure?

Yes, I pulled them dried them with a lighter, and got down along the insulators with blue shop towel to get any crud that worked its way up there. While cranking with plugs in, it would sound like a misfire through the exhaust every so often. I verified the plug wires were where they were supposed to be ect. This car was running with the stovepipe issue. It was only after I attempted to pump 15lbs back in the cooling system while running is when it went to a no start condition. Im wondering if I ruined something else when I did that and the intake was just the start of the issue. The cars not in bad shape at all, but im stumped on this one.

 

[BuickGirlFromMars]

So i completed the job of both intake gaskets tonight. I replaced the lower with the fel pro aluminum, and ended up buying a new dorman plenum with gaskets included. Put everything back together and it still won't run. Every electrical plug is where it belongs, vacuum line in place ect. I pulled the plugs dried them off and even cranked the motor with the plugs removed to clear any oil/coolant that may have been in the cylinders. Put the plugs back, in they were replaced a few months before this all started. It will crank like a champ but will not fire. I'm at a loss of what to look for. Everything seems to be correct but I missed something somewhere. Is there a relearn process or anything that commonly gets missed when this job is done?

return dorman and get the ATP, its better quality.
Removing the plugs and cranking will just inject more fuel. Its probably pooled in the intake if it didnt all go in the cylinder, you need to hold the pedal to the floor or disable the fuel pump. Show some pics of those plugs

And a lighter should not be used on a plug. Get a set of cheap copper plugs if you want to have a set to diagnose with, and have a set of 41-101 plugs for when you fix the issue to put in with a brand new quality set of wires, and use dielectric grease on the boot (not the plug) before putting on. have these ready for when you can do it. Till then, show me your firing order you have hooked up, show us the plugs, and dont do any coolant diag till i clear you to do so

Also disconnect your battery and leave it for 10 minutes before hooking up, we want to get the computer running from fresh and not old learned behavior .

 

[fishinfool56]

Here's a pic. of the plugs. They were replaced not long before this whole situation started. When I attempted to clear the cylinders, I had the fuel pump relay and fuse removed to negate the adding of any more fuel to the engine. I pulled them this morning, and they were wet since I tried to fire it after clearing the cylinders originally. The battery had been out of the for 3 months prior to me starting the repair process on my automatic charger. The obd2 shows no dtc's and the readiness monitors are all showing not ready. This leads me to believe that whatever memory it may have had is no longer present. I verified spark with my spark tester and all seems to be well, blue snappy spark is present. I verified the firing order as well. The coils are numbered, and the cylinders are named the same as an old school small block. Odds on the right, evens on the left, as facing the balancer. I'm going to leave the plugs out today, hopefully letting things dry out a little more. I'm wondering if something else wasn't starting to go wrong along with the intake. It was running until I put 15lbs back on the system while running. I'm thinking maybe I helped a failing head gasket completely fail, this whole issue is strange lol. I will unhook the battery again just in case though.
I really appreciate your responses and willingness to assist over the web.

 

[BuickGirlFromMars]

View attachment 47764Here's a pic. of the plugs. They were replaced not long before this whole situation started. When I attempted to clear the cylinders, I had the fuel pump relay and fuse removed to negate the adding of any more fuel to the engine. I pulled them this morning, and they were wet since I tried to fire it after clearing the cylinders originally. The battery had been out of the for 3 months prior to me starting the repair process on my automatic charger. The obd2 shows no dtc's and the readiness monitors are all showing not ready. This leads me to believe that whatever memory it may have had is no longer present. I verified spark with my spark tester and all seems to be well, blue snappy spark is present. I verified the firing order as well. The coils are numbered, and the cylinders are named the same as an old school small block. Odds on the right, evens on the left, as facing the balancer. I'm going to leave the plugs out today, hopefully letting things dry out a little more. I'm wondering if something else wasn't starting to go wrong along with the intake. It was running until I put 15lbs back on the system while running. I'm thinking maybe I helped a failing head gasket completely fail, this whole issue is strange lol. I will unhook the battery again just in case though.
I really appreciate your responses and willingness to assist over the web.

The only one of interest to me at this moment is this plug here. You see how its white? Do you recall what cylinder you pulled it from?

And these are not the right plugs, they have ribs and i personally see autolite as being a economy (not in the good way) plug brand

The plugs in your car are supposed to be smooth


When things are working right, these are the plugs you want to be using

those autolites appear to be longer insulators, thats going to mess with some things.

I know you said you verified the firing order, but me asking you to send me picture of your engine is 1) for me to double check you
2) for me to spot one of many possible things that could be a problem that isnt evident to you., I have an exceptional ability to analyze/detect things, and you never know. Can you also send me your VIN?
1997 Park Avenues had a TSB for a computer update for a rare issue that caused generic obd2 tools to not entirely work with the cars, and id like to see if that TSB was applicable to your vehicle (i can find out with the VIN)

 

[fishinfool56]

I can't recall which cylinder the whiter plug came from. When I pulled them this morning they were wet with fuel though. I snapped a few pics, i tried to get a few up close as well as a few further back in order to see the vacuum lines to amd fro. ect. Idid try cranking, with fuel not disabled [I forgot to pull the relay]. I did have fuel vapor come from the plug holes. I didnt see any oil, as it did not discolor the firewall any more than it already was. Good call on the whiter plug. Not sure if came out that way or it just wiped up better than the others(which I doubt it did lol).

 

[BuickGirlFromMars]

Did you hook these up
Also, these plug wires are positively shot. They are the original and the front ones are definitely baked and soaked in oil. done. Id get a cheap autozone set at the same time as a set of copper plugs (for your car).


This map sensor is not installed correctly, it will be a vacuum leak and cause wrong readings. reseat the sensor. But before you do, pull the PCV and the spring and the o ring and clean them up and reinstall
nothing about OBD2, but if your scan tool lets you see PCM info or calibration or spec info or controller info, you can get the calibration to check what you have

 

[fishinfool56]

I definitely agree with the

MAP. The Dorman plenum wouldn't allow it to sit 100% correctly. I fiddled woth it for 20 minutes. I did put the new spring,pcv, new seal for the MAP ect. that came with the Dorman. The "clips" were actually different than the Dorman plenum I pulled off ill mess with it some more and see if I can get it to sit correctly. The plugs are still out, once it runs ill grab a set of wires. All I have is a cheap reader, im hoping a guy from work will stop by with a scanner that can show all the good info. Probably going to leave it alone tomorrow, I need a day off from it. Take a look at it with fresh eyes on Monday.

 

[BuickGirlFromMars]

I definitely agree with the

MAP. The Dorman plenum wouldn't allow it to sit 100% correctly. I fiddled woth it for 20 minutes. I did put the new spring,pcv, new seal for the MAP ect. that came with the Dorman. The "clips" were actually different than the Dorman plenum I pulled off ill mess with it some more and see if I can get it to sit correctly. The plugs are still out, once it runs ill grab a set of wires. All I have is a cheap reader, im hoping a guy from work will stop by with a scanner that can show all the good info. Probably going to leave it alone tomorrow, I need a day off from it. Take a look at it with fresh eyes on Monday.

Dorman makes a kit for the PCV that includes a new plastic parts, those often break , maybe you can do that? Then have the extra pcv for maintenance in the future

 

[fishinfool56]

Yea, the Dorman kit came with all the goodies for the pcv as well. I'm hoping that my buddy will come by this weekend with an actual scanner to get a better idea of what's going on. I have a feeling the problem is deeper than the intake gaskets. I think I messed something else up when pressurized the system. Hopefully not but if anything I'll junk it and get the money back for my parts. It kinda sucks if I end up doing that, it's a decent car but if it doesn't run it does me no good.