Chevy Silverado help from the car/truck guys...

HB27

treitz3 wrote: »

If all the guys over the years are right, I do believe I have a closed coolant system. I'll look for the bleeder valves when I go back out there, however, I don't recall having ever seen them before.

I have a question for you though. I take it that I bleed it while it is hot? Logically, I would think so but this is the very first time I have ever worked on an engine of a vehicle of any sort. :eek: Yeah, I know.....scary thought, huh?

You would bleed COLD if necessary. The bleeders (if any) will be the highest point of your coolant system..

Polkersince85

I take it that I bleed it while it is hot? Never open any of the coolant system ports when the engine is hot.

When you change the thermostat, pay attention which end goes toward the engine. Some of them can be put in backwards.

Jstas

treitz3 wrote: »

P1258....Engine overtemperature protection, or low coolant fuel disable is off a website I just found. After further reading, it seems as if the first and second response on this thread may have nailed it. Since I have the part, we'll see if that is the case. *prays* Any valuable advice or is it pretty much cut and dry?

Just take your time. If you don't have access to service manuals, something like a Haynes or Chiltons can be a real good reference to have around. I've never used the Stant directions online but they should be straightforward. It's not a difficult thing to do at all.

Also, even if the gasket looks OK, replace it. Even the O-ring seals work on compression and you will never seat the old one right again so use the new one. Don't use any RTV/Silicone sealant or gasket maker. It'll just cause a problem.



Oh and if you had a catalytic converter problem, you probably would have gotten a P1139 code for a problem with the heated O2 sensor. If the cat was clogged, the O2 sensor would be too far out of range for the computer to compensate on the heated O2 sensor and it would have pushed a code.

Also, since you light is yellow, that likely means your sensors are working just reading too far out of spec. I would bet that you have a coolant circulation problem.


Oh and the thermostat is not controlled by a thermocouple. It is controlled by that spring. That spring actually changes its tension as it heats up and cools down. It is designed to have that spring open up fully at the rated temperature. Usually 180 degrees. That opens that plunger valve attached to it and it lets coolant flow so that the engine doesn't reach the bad temperatures.


As far as codes being useful a "mediocre percentage" of the time, that's a load of buffalo biscuits. Every time I see a light on, first tool I reach for is the code reader to see what's up. It gives you a good idea where to start and if you have decent diagnostic skills and knowledge of the systems associated with that light, you can narrow down that problem pretty quickly. The only time I've ever seen codes being useless was with VW's because they never mean what they say.

Jstas

Polkersince85 wrote: »

I take it that I bleed it while it is hot? Never open any of the coolant system ports when the engine is hot.

When you change the thermostat, pay attention which end goes toward the engine. Some of them can be put in backwards.

Well, the only reason to not open the cooling system when it's hot is because for one, it's under pressure which keeps it from boiling. But the bigger reason is because it is under pressure, the water in the system is superheated. Even with the ethylene glycol changing the boiling point, an overheated cooling system is still well past that boiling point. As soon as you release teh pressure, that coolant turns instantaneously to steam and it increases pressure as well. You aren't going to hurt much on the car releasing it while it's hot. It'll make a big mess but the biggest reason is that you can get serious hurt and/or burned so, those are pretty good reasons to not do it.


But that's a good point on the thermostat. Lots of Chevies and Dodges were like that. They very well may still be like that. It'll have stampings on it showing direction of flow so pay attention to them.

treitz3

Gosh darnit, son of a biscuit eater, Fudging FUDGE! [New Polk rules], it didn't work. I installed the new thermostat and reset the computer/erased the yellow engine light and the same thing happened. Within 12-13 minutes of start-up, I get the same dash reading of "coolant overheating" and the temperature goes up rather quickly, twice as quick with the A/C on.

:mad:

So, it's the radiator or the coolant pump according to what I have heard. What can I do to get these or one of them diagnosed or working?

HB27

Let it run long enough to get warm and shut it off. Feel the radiator from side to side and see if you have warm/cold/hot places in it. It should have uniform temperature across the core. IF you have uneven temps you'll most likely have to replace the radiator.

This is all guess work without being there.

The sensors can be read with VO meter IF you have the specs.

CHeck for excessive play in the water pump, loose belt, etc

Polkersince85

Is it actually running hot? Do you get really hot air out of the heater? Look at the radiator hoses when it is running to make sure that they are not collapsing.

If you wait until it is cold, you could remove the radiator cap, crank it and see if you are getting circulation. Just shut it off before it gets too hot. Be careful though. Not for novices but if you are brave, leave the cap off and measure the temp with a good cooking thermometer, digital with a probe works good. Don't rev the engine,, just idle. Stay away from the opening as coolant could surge out even after you shut it off.

AutoZone should be able to give you the volt readings for the sensor and how to test. Either pull it out to bench test or wait till the engine is cold. A new temp sensor is <$20. Water pump or radiator will be more.

treitz3

You know, I was thinking the same thing last night. The temperature gauge and computer tell me that the engine is overheating but no other indications have been noticed. No steam coming from the engine, no loss of power until the engine switches to 4 cylinder mode, no weird noises and no fluid leaks. I'll check the sensor today as it looks fairly easy to get at and remove/replace.

The OEM part number is 15326388 but unfortunately ALLDATA does not show the specific tests or specifications of the sensor. I'll try to look up how to do that. It would seem as if when the engine is cold and the yellow engine light comes on immediately after start up [engine cold] and the fact that the scanner is reading "Engine Coolant Over-temp Protection Mode" at the same time that it may be the sensor, however, wouldn't the scanner just tell me that the sensor is faulty if that is the case [in theory]?

treitz3

Alright, I found the replacement procedures and I have provided them below, however the "testing" link on this part is not working at this moment in time. I'll have to check back later or look for another website.

Because ECT (engine coolant temperature) sensor procedures vary depending upon their location, first locate the part. You may need to partially drain the engine coolant to prevent coolant spillage.

* Disconnect the negative battery cable.
* Unplug the ECT.
* Then, unscrew it.
* Reverse the removal procedures to install the new part.
* Connect the negative battery cable to the battery.

Gonna try to measure the temperature manually here shortly...

treitz3

Ahhh, found a goldmine of knowledge and testing procedures here...

http://www.wellsmfgcorp.com/pdf/Counterpoint2_2.pdf

Page 3 was very interesting. Apparently I can test the sensor and see live results from the scanner without ever lifting the hood. If it is a wiring issue and not a sensor issue, I'll have to lift the hood but will also be able to diagnose which one may be the culprit.

treitz3

lightman here...It seems there is a possible blockage in the radiator maybe. Pulled the top radiator hose off and checked for flow from the pump. So far so good. Placed the hose back and ran some coolant back into the fill tank and burped it a couple times. Let her run for a little while and the symptoms returned. Gonna try the bleeders next. Any further input is welocome at this point.


Tom's drunk and I'm not. Safety first!

HB27

It sounds like you're right on track. Make sure the engine and coolant system is cool before bleeding out the air.
There are times that cussing the vehicle is required before repairs can be completed properly. The occasional tool toss can pay massive dividends depending on length of the toss. Page 3 of the manual reminds not to throw tools so far they can NOT be found.
The mandatory bruised knuckles also spell out success on a hot day.

treitz3

HB27 wrote: »

It sounds like you're right on track. Make sure the engine and coolant system is cool before bleeding out the air.
There are times that cussing the vehicle is required before repairs can be completed properly. The occasional tool toss can pay massive dividends depending on length of the toss. Page 3 of the manual reminds not to throw tools so far they can NOT be found.
The mandatory bruised knuckles also spell out success on a hot day.

Russ again...Yep the required tool toss has been taken care of.:D Tom's got the cussing down pat and I'm missing some skin off the right knuckles. Gonna let it cool some more and see if the coolant level stabilizes. But it still looks like a clogged system is the culprit. I miss the old days of taking the cap off of the radiator itself and checking for flow. Stupid a$$ closed systems!!:mad:
Tom has pulled a couple steaks out of the fridge!!! Looks like a good meal is coming my way!!!!

HB27

run your hand across the rediator to make sure you have constant temperature across the coil. The radiator core should be even temperature across. It's hard to get to but pretty much required.
You can still check for flow with the cap off but even a partially clogged core can be deceptive as flow in some of the sections may still be present.
I called a buddy still working for a GM dealership and he warned against a chemical flush of the radiator.
He recommened a back flush on the system but was doubtful of success IF the radiator is clogged.
He also said to turn on the heater to make sure any air pockets are filled with coolant. Air locks can be an issue and won't bleed out in the heater core.
Hope it all works out. The steaks and cold brew will sit better.

treitz3

Beer'30 later and this b[female dog]h is going to the dealership. I'm tired of messing with it and I have life to deal with. The steak and noodles were good, I have a date the pillow and my Chevy for the first time has completely pissed me off.

At 8:30 tomorrow, it will become someone else's issue and I will just have to bend over to pay the bill. At this point? I'm down with it.

BIZILL

damn, i hate admitting defeat when it's automobile-related. hope the bill isn't too much there, treitz.

sucks2beme

Most likely the mechanic will toss about $1k in parts at it and it will still come back broken. And they'll keep it at least a week.

treitz3

Naw, I told you these guys always do me right. It did not change this go around either.

Turns out it was a $292.00 bubble. That's it. Went ahead and got a radiator flush while I was at it and they switched out all of the fluids in the coolant system for me. They also installed the coolant thermometer switch I bought. I'm guessing the bubble must have been lodged deep in the engine because Russ and I both squeezed the life out of all of the hoses.

That's one expensive ****. All in all, I'm glad it wasn't the coolant leaking into the engine because that repair would have been about three days and $3,200.00. Turns out I couldn't have gotten the air bubble out without this pressurized machine they have, so all in all, I don't feel too bad. She's back to a steady 210 degrees and runs like a champ again.

Problem solved. Thanks for all of your help fellas as it was greatly appreciated.

TouchOfEvil

treitz3 wrote: »

Naw, I told you these guys always do me right. It did not change this go around either.

Turns out it was a $292.00 bubble. That's it. Went ahead and got a radiator flush while I was at it and they switched out all of the fluids in the coolant system for me. They also installed the coolant thermometer switch I bought. I'm guessing the bubble must have been lodged deep in the engine because Russ and I both squeezed the life out of all of the hoses.

That's one expensive ****. All in all, I'm glad it wasn't the coolant leaking into the engine because that repair would have been about three days and $3,200.00. Turns out I couldn't have gotten the air bubble out without this pressurized machine they have, so all in all, I don't feel too bad. She's back to a steady 210 degrees and runs like a champ again.

Problem solved. Thanks for all of your help fellas as it was greatly appreciated.

Well guess i was right only the ol squeeze was no help this time around. At least it's fixed and nothing was damaged from it running hot.

HB27

Glad to hear you're back up and running. The closed system can be a P.I.A. for sure.

treitz3

Couple of hundred thousand miles later and I have never experienced that bubble in the cooling system again Reading this brought back some memories though. I hit this about 2 weeks ago. Truck is still purring like a kitten with zero major repairs.

Chevy sure does know how to build a dependable truck!

Tom

verb

Gotta laugh at myself here! Reading this thread, feeling your anguish, only to realize this occurred in 2010! LOL! But, glad to hear your liking your truck. BTW what year is is it? That speedo looks very familiar!

treitz3

2004 Chevy Silverado 2500HD, standard cab, long bed. Still mostly stock with the Corvette LS1 engine and arguably the best transmission ever built. Looking forward to hitting the million mile mark with this one!

She sure is fun to drive. Good thing too, as you can see, I drive a lot. I really liked the addition of the cold air intake. Sounds awesome at idle and when she's roaring.

Tom

verb

treitz3 wrote: »

2004 Chevy Silverado 2500HD, standard cab, long bed. Still mostly stock with the Corvette LS1 engine and arguably the best transmission ever built. Looking forward to hitting the million mile mark with this one!

She sure is fun to drive. Good thing too, as you can see, I drive a lot. I really liked the addition of the cold air intake. Sounds awesome at idle and when she's roaring.

Tom

Ah! I thought is was familiar! Although yours received an exterior facelift since I was on the program, I designed the frame and many chassis bits and pieces on that baby!

monepolk

Hey where was this when I had my issue in 2015 on my 2000 Silverado? Never though of searching the forum for my truck issue.

joecoulson

Only issues I have had with mine have been computer/electronic related. Engine (most important part) is flawless.

BDT

Edit...glad you got it sorted.

Air in the system is a PITA. The question is....how did it get there. That's the 64K question.

Also, and OBD2 code reader is a good idea to have.....even if you have no mechanical aptitude, just knowing what the code is helpful...

BDT

verb

joecoulson wrote: »

Only issues I have had with mine have been computer/electronic related. Engine (most important part) is flawless.

Joe I must admit you have a very nice truck! Love the mods, stance is awesome!

joecoulson

Thank You bro!

treitz3

Wait a minute.....you two have met? How did Verb know about the awesomeness of Joe's truck? Inquiring minds want to know...

Shut up Russ.

Tom