having trouble guys.

[CbChevyLt_99]

have a 99 4x4 5.7 tahoe. i recently noticed that after my truck is running for a while and is hot i can grab the radiator hose going to the motor and squeeze it . its soft as shit and i know it should be pretty firm, my truck also wont stop cutting off and jumping when im at idle. it only does the cut off or jump idle occassionaly, and it just idles rough, you can feel it idle rough, its not throwing any codes what so ever either. any ideas what could be causing these problems>? need advice asap as it is my daily

 

[fyremanpat]

Check it with a scanner as it can store codes. Also check fuel pressure and or pump. These pumps are notorious for going bad. With the key in the on position you should hear a "whirling" from the pump.. not a loud whine. Try starting there. What about last tune up?.. as for the hose being soft, did you check the coolant?

 

[X3N0N]

Mileage on truck? If hoses appear to be O.E. and have lots of miles on the truck, go ahead and replace the upper and lower hose. As for the misfire, again if the plugs and wires havent been changed in a really long time then probably time for a tune up. Also spray the throttle body out and get that all cleaned up. Could have a lot of buildup in the throttle body causing the truck to miss and cut out occassionally.

 

[Phil S.]

So I also would check the intake gasket if the hoses don't feel pressurized. What is the coolant level? What does the oil look like? Are you running hot or overheating? I wouldn't be quick to think the low pressure in the cooling system is the same issue as the cutting off and jumping they may be but I would troubleshoot 1 issue at a time.

 

[dsltrc]

Don't forget about the EGR valve... that made mine cut off at lights... i'd just unplug it and see if that helps... it did on mine for a bit but finally i had to put a blank over it and just deal with the CEL (till i can get a tune) , since then, runs nice and no more cutting off or rough running

 

[CbChevyLt_99]

Check it with a scanner as it can store codes. Also check fuel pressure and or pump. These pumps are notorious for going bad. With the key in the on position you should hear a "whirling" from the pump.. not a loud whine. Try starting there. What about last tune up?.. as for the hose being soft, did you check the coolant?

my fuel pump is brand new, i thought about replacing my fuel filter to see if that helped, i did top my coolant off also i think tht solved that issue it was a bit low but i have no clue where it could be leaking from i cant find anything, but motor still cuts off occassionaly and ill check that scanner and let u know if i find anything

---------- Post added at 01:51 PM ---------- Previous post was at 01:50 PM ----------

Mileage on truck? If hoses appear to be O.E. and have lots of miles on the truck, go ahead and replace the upper and lower hose. As for the misfire, again if the plugs and wires havent been changed in a really long time then probably time for a tune up. Also spray the throttle body out and get that all cleaned up. Could have a lot of buildup in the throttle body causing the truck to miss and cut out occassionally.

just did a tune up about 3 or 4 months ago so i know my plugs and wires are good ill check my throttle body and clean it out this weekend when im flushing my brake lines

---------- Post added at 01:53 PM ---------- Previous post was at 01:51 PM ----------

So I also would check the intake gasket if the hoses don't feel pressurized. What is the coolant level? What does the oil look like? Are you running hot or overheating? I wouldn't be quick to think the low pressure in the cooling system is the same issue as the cutting off and jumping they may be but I would troubleshoot 1 issue at a time.

the oil is ok now mixture is happening, i just toped the coolant back off but like i said i cant find any leaks but i know there has to be a small leak somewhere because i have to top it off occasionallly, its never ran hot or overheated at all.

---------- Post added at 01:54 PM ---------- Previous post was at 01:53 PM ----------

Don't forget about the EGR valve... that made mine cut off at lights... i'd just unplug it and see if that helps... it did on mine for a bit but finally i had to put a blank over it and just deal with the CEL (till i can get a tune) , since then, runs nice and no more cutting off or rough running

have any idea what tune your gonna get and how much it would be? and putting that blanket over it doesnt hurt your motor at all?

 

[fyremanpat]

Sounds like the infamous intake gasket leak....if your running rough and leaking fluid somewhere, I'd put money on that.

 

[TigerEyz3]

have any idea what tune your gonna get and how much it would be? and putting that blanket over it doesnt hurt your motor at all?

Computer tunes can range in price widely... I've heard of custom tunes ranging from $75-500.

"Blank" as in he plugged the EGR line. Not "blanket" as is a cover. Plugging the EGR line will cause a CEL to display, but won't cause any damage to your engine, but it may cause lower fuel economy.

 

[dsltrc]

have any idea what tune your gonna get and how much it would be? and putting that blanket over it doesnt hurt your motor at all?

Yeah, I'll likely go with a black bear tune... prices are on their website.. i actually made a blank out of aluminum made it about 1/8 larger than the EGR gasket, drilled some holes for the bolts and then sandwiched that between the gasket and the EGR valve so i could still keep the EGR plugged in (to keep crap out of the plug) also so that if i (or it's next owner) ever want to repair the "EGR problem" then there would be an EGR there and the EGR helps keep the aluminum blank sealed properly to the manifold... i'm getting 14mpg on the highway fully loaded with a family of 5 + a dog... so i'm not complaining...

 

[CbChevyLt_99]

Sounds like the infamous intake gasket leak....if your running rough and leaking fluid somewhere, I'd put money on that.

thats what i got told today lol. do you have any suggestions as to what gaskets or intakes to put on while its apart?>