Plz help..Check ENGINE light 2008 yukon xl Denali

[Garyjw2]

Thanks for taking a second to help out. Everybody on here is really amazing. My last post was about some oil pressure and spark plugs. I got the oil pan gasket replaced new spark plugs and spark plug wires went on a trip drove about 1300 miles everything was going great on the last leg of the journey while going up a hill Towing about a 5500 lb trailer the check engine light came on. The car started overheating and losing oil pressure when I pulled over there was nothing leaking underneath I started back on the road and everything was good until I hit the AC when I hit the little snowflake button I can see my RPMs rev High and then the car starts overheating after about 15 minutes 230 minutes of driving.. I checked the oil everything looks good if I don't run the AC with the snowflake I don't have any problems at all and when you hit the snowflake button does not appear on the instrument panel like it did before. I have to drive back down to family this Friday towing the tt. Thanks anything helps

 

[SunlitComet]

get to any parts store if you can and have them pull your codes and post them here for analysis.

 

[Doubeleive]

don't hit the AC then, your making it overheat, you might need to add a bigger transmission cooler if you are going to be towing again in the future, have the ac checked out when you get back home.

 

[iamdub]

Checked coolant level? Fans running? Does it overheat if you idle for a while? Do the fans come on when you turn the A/C on?

 

[swathdiver]

Compressor is failing causing drag probably. Gotta see the codes and check the operation and pressures of the AC System.

 

[Big Mama]

All true. Start by checking to see if fan comes on. Check stored codes. I’m not sure if it was your post a while back about towing tt over mountains but an aftermarket trans cooler sounds in order. Think there’s more than 1 thing going on.

 

[thompsoj22]

monitor your trans temp, RPM increasing with ac compressor on, imo isnt relative. im sure you are allready white knuckled watching coolant temp but to me it sounds as though a clutch is slipping. Slow down, use the manual shift mode and limit it to 5th while towing on the flats and 4th climbing hills. Accept 35/40 mph with emergency flashers on in the slow lane in 3rd or 4th your climb method and your trans will last longer. Try to keep up with the speed limit/ flow of traffic and you will consume the life of your trans at an accellerated rate.

 

[Garyjw2]

Thanks everyone to responding so fast. Answering kind of questions in order. Going to the store later today to get the codes red and we'll post them here. I was able to get home by just keeping the AC off and then the car runs fine I do feel a slight drag feeling like I'm getting robbed of some power. I'm going to have the AC checked out. Also really like the manual mode I've heard that before that it's better on the transmission. I will be Towing a lot with this vehicle in the future and trying to get it really to be where I can upgrade the main parts that would help with the towing

 

[89Suburban]

No updates on this?