Chad

Random thought thread

18,565 posts in this topic

Start simple and pull the cap on the radiator when cool, let the car warm up and see if your getting any coolant flow.  If not, problem found, replace the tstat.  If you think its a bubble, do the same but lift the side of the car the rad cap is on so its higher than the heater core so any air in the system will head towards the cap and burp itself.  If those simple to do tasks dont clear it up then I say sell it and buy a ZL1...I mean, wait for someone who knows more to chime in!

Matt

mstrpth likes this

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I would guess thermostat or water pump. I doubt you lifted a head. It would have blown the gasket if you did. Don't you have studs in it?

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5 minutes ago, gammey4 said:

I would guess thermostat or water pump. I doubt you lifted a head. It would have blown the gasket if you did. Don't you have studs in it?

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I was going to do head studs, but was told stock was fine.

So stock SS head bolts.....

 

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Even IF the engine had catastrophic failure, why would the dashboard show ----F degrees?  I'd lean toward a totally false temp reading, see also my prior questions...

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There is only one coolant temp sensor.  The same value shown on the dash is the same the pcm sees.  If it gets no reading it probably assumes it's high.  The sensor is on the driver side head next to the header.  The connector is probably broken.

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I'm going to log it again today because this isn't making sense to me. :no: 

How is it not reading temp on the dash, but the log showed 198F and there is only one sensor?

Looked a minute ago and the temp sensor is connected to the connector.

I'll get a picture later.... 

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I'm going to log it again today because this isn't making sense to me. :no: 

How is it not reading temp on the dash, but the log showed 198F and there is only one sensor?

Looked a minute ago and the temp sensor is connected to the connector.

I'll get a picture later.... 

The signal is put out over the canbus to the ecm and also to the bcm which in turn sends it to the dash for your gauges. Bcm also controls the a/c.

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The connector breaks inside the sensor.  You'll have to unplug it to be sure.  I've fixed 2 of these so far and have the connector bodies to do a couple more.

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After the supposed overheat, I cleared all codes.

Drove it 17 minutes today with some stop and idling.

Temp read absolutely perfect the whole time.

Pics of connector:

853645c2b2b400f4fed91cf1c3dd6dd7.jpg

61d21504afc93f302bb1e963bdb4b806.jpg

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6fc957e20076b7033d6a767976feb18a.jpg

e99d06777f11a69d4c7660cecd2f04ee.jpg

2bfae4d83cf424672e5f701de37cfcb4.jpg

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Grab the plastic part of the actual sensor and see if it just pulls straight off. I've had some do that before, Wednesday on a truck I had one.

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So I ran it hard....

Got to the work parking lot with the hood up and the car started getting hotter.

It climbed real quick once it got to about 2/3 and hit 248F before I shut it off.

Fans kept running a while. 

I got video I'll post in a few.

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Not sure if my assumption is right, but I almost feel it has an air pocket in the system.

Because when I check the upper and lower hose, a lot of times they feel like they have no fluid in them.

I took the radiator cap off and the upper hose seems to fill up some and get hot to the touch. 

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Do you see fluid moving with the cap off and it's up to temp?

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Do you see fluid moving with the cap off and it's up to temp?

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I’ll check that and report back. :up:

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@gammey4

So take the cap off and let it get to operating temp to see if fluid is moving? 

Just want to make sure I don't create an air pocket in the system. 

Yes and if you can see the fluid add more

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I think I've figured out my problem with over heating.

I read a lot of forums and everybody that had a boosted LS car that had the issues of of overheating after WOT pull were lifting the heads when using stock head bolts and gaskets at 14 + lbs boost.

The issues are the same no matter how cool or hot it is outside.

Common issues are:

Do a WOT pull and suddenly the car gets hot and over heats.

Coolant level gets suddenly low.

Evidence of blowing coolant out of the coolant overflow bottle.

I had all those symptoms as well. So time for pulling heads and replacing the head bolts and gaskets with ARP head studs and LS9 head gaskets.

Pics of blown out coolant from overflow bottle all in the wheel well

687811e0e8ebd8f8f63adaa750de1f83.png

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Of all those common leaks, how many folks were concerned with knock/detonation/preigniton/octane?    I'd want to be sure that those were non issues before studding.

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Of all those common leaks, how many folks were concerned with knock/detonation/preigniton/octane?    I'd want to be sure that those were non issues before studding.

I’m running about 76% Ethanol right now (at least 100 octane) and some good safe timing.

It only does this after a WOT pull if it get in to peak boost a while.

Picking up zero knock on my logs...

It’s the nature of the beast when running a factory n/a 400hp (330 rwhp) rated engine at approximately 840hp crank (760 rwhp). :shrug:

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