2005 suburban 5.3 surging on highway under load

[Sstevieboy0208]

started a few days ago while going on the highway once I give it gas to go faster it feels like it's missing or surging but no codes or any check engine light. So not sure where to start. But while cruising it's going fine especially going normal speed. I've done some research and it sounds like a fuel to air ratio. So any suggestions would help. The truck have about 225 k on it everything is clean. It shifts fine. So hopefully someone can help me find out what's wrong before I start wasting money.

 

[Doubeleive]

a couple things to check is the fuel pressure and maf sensor

 

[Sstevieboy0208]

Fuel pressure is good. Not sure how to check the MAF

 

[PNWYukon]

Get some Mass Air Flow cleaner and spray it down. Make sure it is totally dry before reinstallation. Big module right next to air filter box, band clamps on each side. Looks like a crazy honeycomb.

Intake manifold gaskets might be something to look at to check for leaks.

 

[Sstevieboy0208]

Get some Mass Air Flow cleaner and spray it down. Make sure it is totally dry before reinstallation. Big module right next to air filter box, band clamps on each side. Looks like a crazy honeycomb.

Intake manifold gaskets might be something to look at to check for leaks.

Does the intake manifold gasket on this engine cause coolant loss and or smoke at cold startup?

 

[PNWYukon]

Does the intake manifold gasket on this engine cause coolant loss and or smoke at cold startup?

Yikes, that sounds like the classic Castech cracked head issue.

You have to remove the valve cover and look for coolant or a crack on the head.

Could be head gaskets if you have overheated before.

 

[Doubeleive]

get some blue devil, takes 2 bottles for the v8's, worked for me, little pricey those 2 bottles will run you about $65

 

[Sstevieboy0208]

Yikes, that sounds like the classic Castech cracked head issue.

You have to remove the valve cover and look for coolant or a crack on the head.

Could be head gaskets if you have overheated before.

No overheating or coolant loss I'm only curious about what I can look at but coolant levels are good and only burns about 1qt oil between oil changes. But still thinking about running Blue devil in it since I have a rear main seal leak and honestly the smoke happened only once while it's 54 degrees outside

 

[Sstevieboy0208]

get some blue devil, takes 2 bottles for the v8's, worked for me, little pricey those 2 bottles will run you about $65

Would it work for oil pan and rear main seal and should I get the rear main seal one of the stop leak ? I'm not losing coolant

 

[Doubeleive]

Would it work for oil pan and rear main seal and should I get the rear main seal one of the stop leak ? I'm not losing coolant

oh, no you mentioned coolant loss and smoke, I only used it myself for a mysterious internal coolant leak, I wouldn't put anything in for oil leaks just get them fixed when you can adding a little oil as needed isn't very costly.