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

treitz3

All is well in the house of Reitz today as I listen to many albums I haven't listened to in quite some time, enjoying every blissful moment of music that comes to my ears. Been doing some gear swapping and [kicker] the kid and wife are gone for just today.....heaven for a Dad, right? Peace, quiet and nothing but being one with the audio Gods..........ahhhhh, bliss.



Well........I go to the store which is 1/4 of a mile away to fill up with gas, get some suds and also get a wash for my reliable Chevy truck of 136,000 miles.

On the way into the car wash, my dash computer says that the coolant is hot. I figure, "so what?". It's hot outside and when I go through the car wash, all will be well. Not so.....

Before I even pull into the car wash, the computer now tells me that the engine is overheating. What? It's only been 1 minute since you told me the coolant was hot! So, I turn the engine off for about 4 minutes as the cat in front of me finishes up with his car wash.

I pull in, at this point hotter than hell inside the cab, and the same thing happens. Damn. OK, so I'm thinking the Chevy dealership is only a 1/4 mile away from me, I'll just go get whatever fixed and get to drinking some cold ones while listening to some more killer music.

WRONG!

I drive about a 1/8th of a mile and the computer now tells me that the engine power has been reduced :eek: So, naturally , I hit the pedal to the metal and literally coasted into the dealership from about a 1/4 mile away coasting into the dealership at a casual 2 to 3 miles an hour, engine off. :eek:

Apparently the heat wave has everybody else in the shop as well and though most everybody there knows me by name and I usually get "magically" bumped ahead of folks to get out? This time, after 6 years of STELLAR service, I got held up by one hell of a traffic jam leading into the dealership. :eek: I'm not in any way complaining as they have treated me better than 99.9% of the companies out there when it comes to the service of my faithful Chevy truck. I just came at a bad time, along with LOTS of other folks.

I have a Chevy Silverado 2500HD, standard cab, long bed 6.0, V-8. Does anybody know or have an inkling as to what may be the issue? It is NOT the coolant leaking into the engine block...that we have verified. If any of you have any suggestions as to what may be wrong? I'm all ears and I've got all weekend, seeing as I'm not going anywhere.

mewisemagic

could the thermostat stuck?

Jstas

mewisemagic wrote: »

could the thermostat stuck?

That's the most likely culprit. Especially at such a random time but not unheard of due to your mileage.

But usually, when it gets that bad, I'm thinking head gasket. But, the new Chevy engines don't eat them like they used to anymore.

You could also just have low coolant or maybe even something as stupid as the relay on the electric fan blew out.

If it wasn't leaking anything it's likely a blockage. Either from funk in the passageways or a stuck thermostat. Those are the first places I would check as well as a leakdown test to see if a headgasket blew.

treitz3

John, if a head gasket blew...what would be the symptoms? Neither the mechanic nor myself noticed anything leaking or abnormal. The fan runs upon start-up at normal operating temperature.

The thermostat or the water pump were the two things that first came to mind. Thing is, it's such a rapid rise in engine temperature [once the engine is warm, it takes less than 5 minutes to go into "protect" mode....where half the cylinders quit firing] that the diagnosis should "in theory" be narrowed down a tad.

Thanks to you both and anyone else who may happen to chime in to help out. It is much appreciated.

treitz3

What would be the procedure to check and see if it's just the thermostat clogged or sticking?

Jstas

Um, exactly what is happening are symptoms of a head gasket leak.

But honestly, I don't think that is the problem. A leak down test or a compression test could easily rule out a head gasket problem.

You probably have a thermostat stuck closed. They are supposed to fail in the open position now to prevent this from happening but sometimes the springs break and they get stuck. The water pump could very well be bad and IIRC, on the newer Chevy engines, it's buried in with the timing gear. But a water pump doesn't have to leak to be bad. You might have something clogging it up and reducing efficiency or flow. It's hard to tell but a thermostat and water pump are fairly easy and cheap fixes. I'd give you exact numbers but my ALLDATA discs are packed away right now since I'm in the middle of moving.

Jstas

treitz3 wrote: »

What would be the procedure to check and see if it's just the thermostat clogged or sticking?

The procedure? Pull the thermostat out and replace it. It's usually about $8 and takes a whole 30 minutes. Most are in easily accessible places now and they are so cheap that it's easier to just replace the thing since you had to dig it out anyway.

Jstas

Yeah, a water pump, if it's bad, will be between $75 and $100 depending on where you get it. Barring it being a head gasket problem, it shouldn't be a super expensive fix. Unless something else is wrong like a clogged radiator or something.

treitz3

Jstas wrote: »

I'd give you exact numbers but my ALLDATA discs are packed away right now since I'm in the middle of moving.

ALLDATA you say? Well, if what I see is what you used to be able to see then we may be able to diagnose and correct the issue in short order. I just fixed the A/C on the same vehicle for $160.00 shipped for what two dealerships wanted to do for between $999.00 and $1,150.00. All it took was 20 minutes of my time and a little bit of research.

Jstas

Yes, ALLDATA. It's awesome stuff. It can turn a good mechanic into a pretty **** smeller...I mean a pretty smart feller!

mewisemagic

Jstas wrote: »

The procedure? Pull the thermostat out and replace it. It's usually about $8 and takes a whole 30 minutes. Most are in easily accessible places now and they are so cheap that it's easier to just replace the thing since you had to dig it out anyway.

what he said, go to parts house and get one and change it out. on chevys they are close to the top radiator hose outlet on the manifold

Polkersince85

Test your coolant temp sensor and wire harness also. A lot rides on its output.

BIZILL

so the problem persists? or was it just a fluke? my girlfriend's '01 avalanche did the same exact thing, as i'm told. she pulled over and let it cool down. after like half an hour or so she told me she started back up and all was well. i thought she was bullshittin', but her pops is a mechanic, so she doesn't embellish too much on the automobile front. anyway, needless to say we keep our eyes on the temp gauge whilst in perpetual paranoia.

good luck.

TouchOfEvil

Did you not look at the temp gauge? Just curious.
It's a good idea to take a peak at the coolant tank from time to time.
These trucks have a long history of air bubbles in the cooling system. You can often squeeze the hose while the truck is running with the cap off to release the bubble. I have two of these trucks myself.

BIZILL

i think i've asked you before, touchofevil, but not sure you ever responded. is that/was that you over at fullsizechevy.com and/or gmfullsize.com?

TNRabbit

Tom, have you ever used radiator stop-leak on it? (Bad)

What have you done recently to the engine?

HB27

I just saw a 2007 Chevy truck with a stopped up radiator about a month ago.
I was at my buddy's shop and the guy had come in 3 times for the same issue.
It turned out to be ok under most normal driving but when the fella tried to pull his little trailer or drove it harder than normal it over heated fast. Just a little FYI as even a fairly new radiator can have issues.

treitz3

Here's a hookup for a OEM water pump I was able to find online. ALLDATA says that the dealership would want around $250.00, plus 3.6 hours of labor and I think the going rate is $95/hour. Ouch.

http://www.carpartswarehouse.com/parts/19-40001.html

These guys want $125.00 shipped but I will have to wait until Wednesday to get it shipped to me. No biggie, I can wait.....but the 3.6 hours to install? That [honestly] has me a little intimidated. :eek:

I started it up this morning and the engine light immediately came on. I let it run for about 11 minutes and the temperature gauge read 240 degrees. It's normally at 210 degrees all day long, no matter what I'm hauling or how I drive. Yesterday, when the engine reduced to 4 cylinders, the temperature was at 260 degrees.

Gary, I have not used a radiator stop leak on it before and I have done nothing but getting the oil changed lately. In fact, besides the 90,000 mile checkup and transmission preventative services, nothing but oil changes have been done to the engine/drive train. The only issues with the truck so far [that I can recall] has been with the A/C [fixed], a couple of light bulbs that bit the wind and tire replacements. Not bad at all for a truck with 130,00+ miles IMO.

TOE, I checked the coolant level this morning and it is spot on. Went ahead and tried your recommendation of squeezing the hoses while the engine was running and the cap off. No change noted.

Polkersince85 wrote:

Test your coolant temp sensor and wire harness also. A lot rides on its output.

Thanks you for your suggestion, how might I go about doing this? I haven't run across any tech notes, as of late, that describes how this is done.

John, I'm currently looking up the thermostats. I believe it is part number 12581595. As soon as that's verified, I'll posts a link to see if I've got the same component you are talking about. I'm going back outside right now to see if the catalytic converter may be clogged.

treitz3

Ahh, just called AutoZone and they have the thermostat in stock with the seal for $13.00. I'm on my way.....

Jstas

OK, that engine light is not going to go off until the code is reset in the engine computer. If you have a code reader, that will probably tell you what the problem is. However, it's likely going to say that the coolant temp sensor is reading hot coolant. So that's not much use there. But, I wish I had caught you before you left 'cause AutoZone will read the codes for you and you can look them up online.

As far as where to get parts, by far, Rock Auto has been the cheapest and easiest to deal with. They have an impressive inventory as well.

http://www.rockauto.com

I use them often since they stock every Motorcraft part in existence and they beat my local dealers by at least 20% on price.

As far as the catalytic converter, do you have any yellow lights on in the dash? Red lights usually mean a mechanical failure like no oil pressure, too high coolant temps, misfires or no manifold pressure and such. Yellow lights usually mean a sensor somewhere is out of spec and the management computer is reporting a fault. It usually has to do with emissions. But a clogged cat would have a yellow light because the O2 sensors going in would be very far off from what the O2 sensors going out would be reading. You can check it but I don't think that would be the problem. It certainly wouldn't heat up that fast if it was and you would have noticed a gradual drop in power and fuel mileage over the last few months.

TouchOfEvil

BIZILL wrote: »

i think i've asked you before, touchofevil, but not sure you ever responded. is that/was that you over at fullsizechevy.com and/or gmfullsize.com?

I don't recall you asking...may have and i didn't see it. But, yes that is me. Same user name except i had a 04 at the end. I'm also on performancetrucks.net

TouchOfEvil

If your pump ends up being bad don't let the time bother you. It's not as hard to do as the time length required leads you to believe.The cats do clog so maybe... i hope you get it all fixed up soon. I had to replace my e-fans on my 00" yesterday as they took a massive dump on me lol.

treitz3

Well, I ended up getting the thermostat. I have to be honest, it does not look like any thermostat I have ever seen. Nothing electronic whatsoever and it looks kinda like some sort of weird gas cap with a spring or two. Interesting.

Anyhoo, while I was there I went ahead and purchased an Auto Scanner Plus. It's a CP9580 model that should make repairs on my two vehicles a little easier [hopefully]. Here's the one I got....



I'm gonna sit back and listen to some tunes and then do a little bit of research on how to get to this thermostat properly replaced. It's a Stant thermostat and apparently they have a website that has the installation instructions. I'm sure it's simple but I want to make sure I don't screw something else up while this goes in.

Before I install it, I will hook up the scanner and see what codes it gives. This particular one will give me display on the emissions status, on screen code definitions, live engine data, top and frequently reported fixes for said codes and it is also vehicle, model and year specific. Never used one of these before but it sounds pretty damned cool to me. After I am done with the repair, it will also erase the yellow engine light.

treitz3

John, it's just the yellow engine light. No red lights. Also, no drop in power and fuel mileage noticed over the last few months. She's been running like a champ.

HB27

IF your truck has a closed coolant system one air pocket can give those readings also. IF it's a closed system you'll see "bleeder valves" high on the cooling lines.
And code readers are only good for a mediocre percentage of the time but they do give a good place to start looking. I used to be a GM tech doing "line" work.

TouchOfEvil

HB27 wrote: »

IF your truck has a closed coolant system one air pocket can give those readings also. IF it's a closed system you'll see "bleeder valves" high on the cooling lines.
And code readers are only good for a mediocre percentage of the time but they do give a good place to start looking. I used to be a GM tech doing "line" work.

I said the same thing and he gave it a shot but there was no change.
Also the t-stat is really easy to replace. Just take your time and it should be fine.

treitz3

HB27 wrote: »

IF your truck has a closed coolant system one air pocket can give those readings also. IF it's a closed system you'll see "bleeder valves" high on the cooling lines.

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?

treitz3

OK, I checked the computer. All systems check OK but but I did get a code P1258 which according to the Scanner is the "Engine Coolant Over-temp Protection Mode". It shows it as being active. I did not see any bleeder valves.

Jstas

Yeah, that means the engine is overheating because the coolant is too hot.

Either your thermostat is bad, your radiator is clogged or your water pump is bad.

I really doubt it's the catalytic converter.

treitz3

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?

TouchOfEvil

treitz3 wrote: »

OK, I checked the computer. All systems check OK but but I did get a code P1258 which according to the Scanner is the "Engine Coolant Over-temp Protection Mode". It shows it as being active. I did not see any bleeder valves.

You will have to have the code removed before it goes away. However you will need to fix the issue first or it will just come back on if it gets hots enough again.