Bad Thermostat? Heater Core?
#31
01-26-2014, 07:52 AM
Join Date: Apr 2010
Location: Mentor, Ohio
Posts: 12,156
I've used the one with the Dorman kit with no issues.
I found changing the LIM gaskets to be a pretty easy job, part of the job that takes a lot of time is cleaning all the parts.
I found changing the LIM gaskets to be a pretty easy job, part of the job that takes a lot of time is cleaning all the parts.
#32
01-27-2014, 08:09 PM
Slight update. Got down to the bolts for the LIM, it'll come off tomorrow. No real problems to speak of except....the first five exhaust nuts/bolts came out fine, then the last one sheared. I got impatient and didn't let the PB penetrate enough. So it's on the back flange (closest to the cabin), and I got the first nut off that holds the heat shield, then I sheared the next one that is a threaded fastener/nut. So how is the other half of that stud secured to the back of the flange? Hopefully it's just self retaining and I just need to hammer it out? Or do I just PB the crap out of it then put vice grips/Channellocks on it and twist it out?
Also, why is my throttle body, UIM, and LIM all covered in black soot? I mean, I understand what the black soot is, but is something I do (or don't do) causing that? At a minimum, it's annoying when it sticks up my TB, but other than that, it just doesn't seem right. Anything I can do on this?
Also, why is my throttle body, UIM, and LIM all covered in black soot? I mean, I understand what the black soot is, but is something I do (or don't do) causing that? At a minimum, it's annoying when it sticks up my TB, but other than that, it just doesn't seem right. Anything I can do on this?
Last edited by farmerjg; 01-27-2014 at 09:36 PM.
#33
01-27-2014, 09:38 PM
Join Date: Apr 2010
Location: Mentor, Ohio
Posts: 12,156
That's not soot. It's actually caked on oil and it's normal, not a sign of a failure. Right now I'm having a brain fart and can't remember what the story is on that (perhaps someone else can weigh in on this one).
Also, I may be missing something or getting confused (or just late and out of my mind lol). Why are you removing exhaust bolts? Unless you are taking the heads off, upgrading the manifolds or replacing an exhaust gasket, they don't need removed for a LIM gasket job.
Also, I may be missing something or getting confused (or just late and out of my mind lol). Why are you removing exhaust bolts? Unless you are taking the heads off, upgrading the manifolds or replacing an exhaust gasket, they don't need removed for a LIM gasket job.
#34
01-27-2014, 09:45 PM
I couldn't get to the bottom throttle body nut. I had taken off the throttle body before with the crossover on but it was difficult and I couldn't get it this time so I opted for removing the crossover (the guy who did the Bonne writeup also recommended removing). Clearly this was not the correct choice as I'm now left with a broken stud. I also figured with the EGR it would help.
#35
01-29-2014, 04:47 AM
FYI - From my experience....
If you have a bad LIM gasket, a radiator pressure tester will almost always (in my experiences it always did), exploit that problem (air/coolant normally bubbles to the outside of the engine).
Now, with head gaskets, I did have a failed head gasket causing me a bunch of problems on a 3100 engine. Every single time I put pressure on the cooling system with the tester, it never dropped. I put the tester to the max pressure for the rad cap. A couple of times, let it sit for an hour and it never lost one bit of pressure. In that situation, the cylinders were forcing compression gases into the cooling system via a crack in the head gasket, causing an air pocket in my cooling system and to over pressurize the system and temp gauge to read all sorts of crazy readings.
When you turned the car off, because the cylinders put so much pressure in the cooling system, it blew out the rad cap and even back into a cylinder (causing some short lived rough idle and later as it got worse a moment of big white clouds from the exhaust).
When I finally got some input confirming head gaskets, I tore it down and sure enough, bought head gaskets had a crack that only showed if you twisted the gasket and it went from a coolant jacket to a cylinder.
If you have a bad LIM gasket, a radiator pressure tester will almost always (in my experiences it always did), exploit that problem (air/coolant normally bubbles to the outside of the engine).
Now, with head gaskets, I did have a failed head gasket causing me a bunch of problems on a 3100 engine. Every single time I put pressure on the cooling system with the tester, it never dropped. I put the tester to the max pressure for the rad cap. A couple of times, let it sit for an hour and it never lost one bit of pressure. In that situation, the cylinders were forcing compression gases into the cooling system via a crack in the head gasket, causing an air pocket in my cooling system and to over pressurize the system and temp gauge to read all sorts of crazy readings.
When you turned the car off, because the cylinders put so much pressure in the cooling system, it blew out the rad cap and even back into a cylinder (causing some short lived rough idle and later as it got worse a moment of big white clouds from the exhaust).
When I finally got some input confirming head gaskets, I tore it down and sure enough, bought head gaskets had a crack that only showed if you twisted the gasket and it went from a coolant jacket to a cylinder.
When checking for a bad head gasket using a pressure tester you need to remove the spark plugs. Otherwise the pressure leaking past the gasket into the cylinder has nowhere to escape and you'll end up with a steady pressure reading.
#36
01-29-2014, 08:18 PM
And finally, I'm done! Outside of a broken exhaust stud and having to chase one of the head threads for the LIM bolts, it went about as I expected it to. This is by far the hardest thing I've ever done, and consequently it is the most rewarding. Just as a comment, in hindsight, after seeing the FelPro gaskets next to the ones that came out, I guess I can't say I'm all that surprised that they eventually failed....they just didn't seem all that robust.
So, as follow on questions;
Why do our heads have two coolant ports per head if the LIM only has one per side?
On my head and on the LIM, I had a decent amount of milky/pasty sludge. I presume that's where my gasket had failed and oil was mixing with coolant?
And final thought, I could have saved myself an elevated heart rate if I had known that PB blaster smokes once the exhaust gets hot again.
Thanks for all the help everyone.
So, as follow on questions;
Why do our heads have two coolant ports per head if the LIM only has one per side?
On my head and on the LIM, I had a decent amount of milky/pasty sludge. I presume that's where my gasket had failed and oil was mixing with coolant?
And final thought, I could have saved myself an elevated heart rate if I had known that PB blaster smokes once the exhaust gets hot again.
Thanks for all the help everyone.
#37
01-29-2014, 08:50 PM
Join Date: Apr 2010
Location: Mentor, Ohio
Posts: 12,156
First, congrats on finishing this job! It's intimidating the first time! But as you said, it's also rewarding!!!
I think the answer to your head and two coolant ports might be an easy "assumption" (that's right, I'm assuming, guessing at this). The front and back head are 100% the same. What makes them different is in what they have bolted to them. Otherwise, same casting. That being said, I don't think GM wanted to design a front and rear head. And you want the coolant to flow through as much surface area as possible. I wondered what would happen if you opened the other two ports on the LIM, and I'm a little concerned this would have a negative effect (but I'll admit, I never studied it enough).
The last reason, GM uses the same heads on the L36 RWD F-body and I'm assuming on the 3.8l Holdens in Australia (both that have different intake setups). Perhaps those intakes use different coolant ports or maybe all coolant ports.
I think the answer to your head and two coolant ports might be an easy "assumption" (that's right, I'm assuming, guessing at this). The front and back head are 100% the same. What makes them different is in what they have bolted to them. Otherwise, same casting. That being said, I don't think GM wanted to design a front and rear head. And you want the coolant to flow through as much surface area as possible. I wondered what would happen if you opened the other two ports on the LIM, and I'm a little concerned this would have a negative effect (but I'll admit, I never studied it enough).
The last reason, GM uses the same heads on the L36 RWD F-body and I'm assuming on the 3.8l Holdens in Australia (both that have different intake setups). Perhaps those intakes use different coolant ports or maybe all coolant ports.
#38
01-30-2014, 05:52 PM
Drove all day today and everything was good. I noticed my temperature was living on the mark that would be the equivalent of 177.5....did I likely get a 180 t-stat? Or did I bleed incorrectly and I've got air in the line? Factory is 195?
Also, I never paid attention to oil pressure in the past. On my drive today, under power, my dial was halfway from top dead center to the 'H' mark. Does that sound right?
Just so it's here, I wanted to post a picture of what my heads looked like.
Also, I never paid attention to oil pressure in the past. On my drive today, under power, my dial was halfway from top dead center to the 'H' mark. Does that sound right?
Just so it's here, I wanted to post a picture of what my heads looked like.
#39
01-30-2014, 11:32 PM
Join Date: Apr 2010
Location: Mentor, Ohio
Posts: 12,156
If I am understanding things correctly, 177.5 does not sound like a need to be concerned as long as the car is blowing hot air from the vents inside. If so, consider it good. Air pockets normally cause CRAZY high readings.
And if I recall how my oil pressure responds, that sounds normal too.
I assume you changed the oil immediately after completing the gasket changes? If not, do it ASAP (as coolant and junk can get down where it doesn't belong). Also, I tend to make the next oil change in about 1000 miles (early) on purpose as an extra precaution (it might be overkill, but it never failed me).
And if I recall how my oil pressure responds, that sounds normal too.
I assume you changed the oil immediately after completing the gasket changes? If not, do it ASAP (as coolant and junk can get down where it doesn't belong). Also, I tend to make the next oil change in about 1000 miles (early) on purpose as an extra precaution (it might be overkill, but it never failed me).
#40
02-01-2014, 08:22 PM
Thanks for the advice on temp and oil. I got the oil changed this morning and it appeared to be fine. Obviously I wouldn't be able to see any little things like foreign debris, but there was no discoloration in the oil that would make me believe coolant had gotten down there. I went through a lot of effort (compressed air and a vacuum) to make sure all coolant was out of the LIM before I pulled it off.
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