Hi every one,
I have 2005 5.3 Tahoe and today I toke it for oil, spark plug and wire change, after that the temperature went to max, the fan is working no thermostat and no smoke or noise.
I suspect something wrong in the engine, but what can make overheat?
a. head gasket bured.
b. crack in the head.
c. crack in the cylinder.

what and why?

 

Check and see if the coolant is low. Check and see if there is water in the oil, if so it is a head gasket. I would suspect if you just had some work done it is a damaged sensor. When you crank the motor does it imideatly go to max temp or does it slowly creap up? If it just jumps up it may be the sensors. I would call who ever did your work (if it was not you) and ask them what to do. If it was you I would check the two temp sensors and make sure they are hooked up and functioning. Did they service the radiator? if so you may have an air bubble in the block. I just fought that battle myself.

 

The no thermostat if stated correctly is your problem you need a thermostat for daily driving, if you removed your t-stat why did you do it?

 

Check to see that they did put oil back in it!!!!!! My sister took her spankin new van to the dealer for a oil change. when she left the low oil light was on. guess what????? They didn't put No Fkin oil back in it... so it can and will happen.. I'd personally would like to beat the Idiot with a pipe and tell him to quit drugs. if it has oil, ask what kind. if it happened just after the oil change I think it's oil related. even the totally wrong spark plug heat range wouldn't be that bad. just my .02

 

will I checked every thing before taking it to the dealer (they will give a report tomorrow).
it's not the sensor because the temp go's slowly.
I suspect the head gasket, but there is no water in the oil, I had replaced the cam and the spring valve so I think that the old gasket was reused.

 

oh and for the no thermo, I removed it for checking that the thermostat wasn't blocked.
but even without thermostat you will have coolder engine I think.

 

update,
I got the first report from the dealer, the head gasket was burned.
and they send the head for checking.
as I am curious to learn I hope all to participate in this thread, now why the gasket was burned?
I have 3 scenarios:
1. my electric exhaust cutout was faulty it was closing and opening randomly.
2. the gasket wasn't installed corectly or it was reused.
3. the thermostat was blocked for a moment until the temp reaches the read line and then the gasket burend.

 

That is a big misconception the engine will not run cooler, in fact for daily city driving the enigine will overheat because the coolant will not spend enough time in the radiator to dissipate heat before returning to the engine. The thermostat open and closes during normal driving but your temperature gauge does not show it because it's located on the block. Most thermostat are designed to fail open not closed because if they did not open, the thermostat makers would be facing a lot of lawsuits for blow engines.

The last time I had an overheating problem in my truck the thermostat was stuck wide open, I knew because it was open when I pulled it out, a new thermostat corrected the problem

Scenario 1 will not cause burnt head gasket unless you have cutouts located on every primary tube next to the head.

Scenario 2 is you best bet, I have never heard of a mechanic who will not push new head gaskets when R&R (Remove & Replace/Reinstall) the heads.

Scenario 3 is a very possibility but the blockage would be air if the crossover pipes, connects the heads together to bleed off air, were plugged up or damaged when the heads were removed.

Another possible scenario would be whoever installed you cam and springs reused the head bolts, or used new ones and did not torque them down properly. Since the heads are off try to get some ARP head studs installed.

 

I had the slow creeping temp to max problem today. Just fixed today. When my motor was delivered to me, the head gasket was on backwards. Make sure the gasket is on correctly, and make sure it's the CORRECT gasket. The gaskets changed from '02 on up. I verified this today, and the gasket material changed that year as well.

As stated in the previous post, if those vent tubes (I-style, or otherwise) are blocked, or there's an air pocket in the system, it'll do that. Do what I do, remove the vent hose (rubber hose) that comes off the radiator, thru the throttle body, and into a metal tube behind the alternator. Remove it from behind the alt. Make sure a STEADY stream of coolant comes thru (may take about 45 - 60 seconds). Once it's steady, air pockets should be gone. It would be best if the motor was on an incline too.

Good luck!

 

So whats the latest? Have you heard anything?