My newly driving16 yoDS's Tahoe has been running warmer lately. Here are the symptoms and maybe you can help "diagnose" the problem-if any. When we first got the Tahoe it had 98,500mi, now it has 101600. It has never ran warm before-always a little below the 210 mark. In August son put on K&N cold air intake kit, then DH and I bought him Flowmaster dual exhaust for his BD. We also had the intake manifold gasket replaced as well as the water pump and some hoses. Radiator was supposedly flushed with new coolant put in. I drove the Tahoe home from getting the Flowmasters on (vrooom vrooom-hee hee) and it was running super coolcloser to the mark that would indicate over a quarter tank if it was a gas gauge. (sorry don't know how else to describe it)
Lately (last 3 weeks) son says that Tahoe has been running at closer to 210 and sometimes a little over especially if he is driving at a sustained speed -say on the freeway for a good distance. So I took it out yesterday. It was already warm since DS had just driven plus it was over 100 here yesterday[]. It started out with the needle on 210, then went down as I granny drove it on a 35MPH road towards the freeway. As I got closer to the freeway, the gauge started climbing and when I got on the freeway and went about 2 miles at 60-65 mph, it was at 210 and even went slightly above. I did notice at one point the needle "bounced" up and down and I asked son if this had happened before,he said yeah. As I granny drove home, the needle went slightly down past 210-not a mark but in between 210 and the next lower little mark. This car never got that hot before and now with the K&N etc I expected it to be much cooler. With the temp needle "bouncing" every now and then, could that be a thermostat problem? Son says it doesn't get hot going in town stop n go, just on highway or freeway where speed is sustained for a distance.
I want to try and get some idea as to what could be wrong before my DH (aka not a mechanic) tears into it. Anyone have any ideas? Oh and before I forget, if the Tahoe has been sitting for several hours or overnight, it will have some dripping out the exhaust when you stop and turn it off. Is this normal with the Flowmasters? For some reason it seems more on the right side.[]

 

Mine does something similar... it will run 210-220 99% of the time, then sometimes it will go all the way up to 240-260... by then i crank the heat, roll down the windows, and as quickly as it went up... it goes back to 210... like nothing was ever wrong.

its all factory, minusa new water pump, heater core, and radiator.

211,000 miles, 1995 Tahoe 2DR...

I love my tahoe to death, but I only need 1 more year of out of to pay off my Jeep; and buy a used 09 Tahoe LTZ...

so I haven't really 'tried' to diagnose the 'problem'...

infact, all summer it had such a coolant leak, that I ran mostly water to cool it... now that I replaced the heater core, and used fix leak in the radiator, its back to antifreeze and water...

1 more year baby, 1 more year... 211,000 miles, and EVERYTHING worked until this summer (A/C went).... I see no reason to fix the A/C when its 60 degrees out... it will wait till spring

sorry if this isn't a huge help...

with the age of the vehicle you come to expect some flaws...

you could try a new thermostat $5-$10

or new temp sensor

ohh, and my power mirrors died years ago... both of them? it may be a fuse, but i'm the only who drives it, so i never looked... maybe I'll do that today... I've owned it 7 years, and never checked the power mirror fuse (if it exists)....

if your close to Harrisburg, PA I will let you know when 'Betsy' is for sale, maybe you can use the parts god I will miss this truck... its been to Cali and back with me

 

I agree w/ STS. I'd try a thermostat even if it's recently been replaced. You'd be surprised how many are bad out of the box.

 

As far as I know, the thermostat has NOT been replaced, only the water pump, intake manifold gasket and some hoses. When I saw the gauge needle jumping that is what I thought since I have had a car w/ a bad thermostat before. But what do I knowI'm a housewife! I hope that is what it is so I can ITOLDYOUSO to the males in my household!

 

Now, now. Might want to keep that one in reserve for when you really need it. You know how fragile us guy's egos are.

 

I second or third the thermo replacement, I think the factory one is 195F you could try the 180F but don't go any lower or you will start loosing MPG running it too cool...

 

I'm on my 3rd thermostat,I think... who ever came up with 210 as the magic number?
the inside of my cooling system after 13 odd years is umm.. not pretty?

 

ITOLDYOUSO

Yep, i got to utter those words!