Another dealer misdiagnosis?

[CNR2011]

I recently had the dealer tell me my 04 LB7 needs head gaskets. They said it had too much pressure in the rad hose. It runs great and I dont lose any coolant. A mechanic friend of mine did injector cups and a compression test for me just recently. 400 psi on all 8. Plus he said he pressurized the cooling system with the glow plugs out and didn't lose any coolant or pressure after he did the cups? Is the dealer out to lunch? If the cap is rated for 15psi, wouldn't compression gasses exceed that causing me to lose coolant out the overflow? I also noticed it's been running colder than usual since injector cups. Thoughts?

 

[TheBac]

Injector cup not sealed properly might be an issue.
Worn out Tstats?
Cooling system not bled/air in system?

 

[chevyburnout1]

What did you take it to the dealer for in the first place? What is your original complaint? Leaking cups can make the hose hard but only loose slow amounts of coolant. Took over a month when mine were leaking to pop up the low coolant light.

 

[Awenta]

Why did you need to reseal the cups to begin with?

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[CNR2011]

It was at the dealer for a service. I needed one done in a pinch. I had the injector cups done at the same time as injectors about 3 weeks ago. No complaints since. Truck runs strong. No coolant leaks. And never noticed excess pressure in cooling system. But did notice it running cool. Perhaps stuck t stats. Or maybe air in cooling system still. If it's head gaskets then it is what it is. But I don't want to spend the dough when my truck seems to be good. And it had 400 psi on all cylinders. And of course the dealer won't be doing the job if it is.

 

[CNR2011]

Also, I talked to my mechanic buddy and he said he used 272 Loctite with new cup seals and the sealing surface on the cup and head were cleaned and inspected for damage. Seems like he did it right from what I can read.

 

[battlegraduate09]

So they just said your radiator hose was hard ? Have you seen yourself if there is pressure in the cooling system after a drive and sitting for 12 hours

 

[CNR2011]

So they just said your radiator hose was hard ? Have you seen yourself if there is pressure in the cooling system after a drive and sitting for 12 hours

Yes they said, "you have a lot of miles on this truck and excessive pressure in the reservoir so basically we won't do any more diagnostics until you give us the head gasket job". (Well that's what I got out of it anyways) There is pressure there but not enough to blow out the cap and on the ground. I don't typically check my rad hoses in the morning but I'll give it a try.

 

[battlegraduate09]

Does your truck have an egr still? Just kind of curious myself because my truck has developed some pressure in the cooling system also, radiator hose is not soft but not hard either. Mine developed after I deleted mine and had a cold water leak at the heater core. Another thing to check is idle the truck with the cap off and check for any bubbles in the surge tank. They will be small and many of them If the head gasket is blown.

Its not a surprise they said something like that really. I see head gasket jobs go for around $4500-5,000 here at dealers

 

[Henry95]

Does your truck have an egr still? Just kind of curious myself because my truck has developed some pressure in the cooling system also, radiator hose is not soft but not hard either. Mine developed after I deleted mine and had a cold water leak at the heater core. Another thing to check is idle the truck with the cap off and check for any bubbles in the surge tank. They will be small and many of them If the head gasket is blown.

Its not a surprise they said something like that really. I see head gasket jobs go for around $4500-5,000 here at dealers

I was quoted 6800 for a head gasket job in Fort Saskatchewan Alberta by the GM dealer. Told them to fly a kite only paid another 200 more for the truck. Ended up doing it myself.


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[CNR2011]

Truck is bone stock. No deletes whatsoever. I'll check closely for bubbles in the reservoir. Will the bubbles only show up when warm? Cause it only gets up to 160 at most right now.

I can't stand dealer diagnostics. I know they are good techs but I feel they cover the bases only. And change all parts related to the symptoms... My friend with a 6.0 Ford was quoted a new HPOP, injectors and FICM from the dealer just for a no start. The same mechanic who did my injectors/cups fixed his truck for under 300 bucks. Was just an IPR solenoid.

 

[battlegraduate09]

I usually cbeck at operating temperature because well.. they are usually at operating temp when people bring them to me. Keep us updated

 

[chevyburnout1]

Truthfully I wouldn't worry about it. Chances are it was a dumb lube kid doing the services and he went to open the coolant bottle to "check the coolant" and it may have released some pressure. Which to him means head gaskets... I would want a complete diagnosis (how much pressure it builds while running, leakdown, etc) before condemning anything. You're probably fine. Maybe it burped a bit after doing the injectors and the coolant was slightly low. Top it off and drive it.

Just because it was serviced at the dealer, doesn't mean you had master ASE/GM techs doing the oil change I worked at the dealer for seven years and the lube kids there weren't any better than Grease Monkey.

 

[CNR2011]

Truthfully I wouldn't worry about it. Chances are it was a dumb lube kid doing the services and he went to open the coolant bottle to "check the coolant" and it may have released some pressure. Which to him means head gaskets... I would want a complete diagnosis (how much pressure it builds while running, leakdown, etc) before condemning anything. You're probably fine. Maybe it burped a bit after doing the injectors and the coolant was slightly low. Top it off and drive it.

Just because it was serviced at the dealer, doesn't mean you had master ASE/GM techs doing the oil change I worked at the dealer for seven years and the lube kids there weren't any better than Grease Monkey.

I hear yah. Thanks! It's a bit unnerving when someone tells you that you need like 6k of work when the truck seems fine. I think I'll try thermostats first, I can do that myself. Is there a proper procedure for bleeding air in cooling system? I know that with all my cars or trucks in the past, just running it with the cap off and squeezing the upper rad hose was enough. How about our trucks? Same?

 

[battlegraduate09]

I have a snap on air lift for filling coolant because most new vehicles require a full vacuum to be pulled on the system before filling coolant. To avoid air pockets at least. Maybe a parts store would have something similar you could rent. That would be the most sure fire way after you do thermostats. Also I read on here if you remove the t stat housing and belt idle the engine and whichever t stat hole bubbles is the side of the engine the head gasket is blown. I have never used this method because it makes sense to do both at the same time anyways due to the labor of everything that needs to be removed to do headgaskets. Also since the water pump is gear driven it seems to me like it would make a big mess but like I said never tried it

 

[rg3whitelbz]

Why would removing the belt make a difference? Fan air?

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[x MadMAX DIESEL]

I have a snap on air lift for filling coolant because most new vehicles require a full vacuum to be pulled on the system before filling coolant. To avoid air pockets at least. Maybe a parts store would have something similar you could rent. That would be the most sure fire way after you do thermostats. Also I read on here if you remove the t stat housing and belt idle the engine and whichever t stat hole bubbles is the side of the engine the head gasket is blown. I have never used this method because it makes sense to do both at the same time anyways due to the labor of everything that needs to be removed to do headgaskets. Also since the water pump is gear driven it seems to me like it would make a big mess but like I said never tried it

That won't work because both heads are tied into both thermostats. One just opens at a higher temp to give more steady temperature.


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[battlegraduate09]

Why would removing the belt make a difference? Fan air?

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That won't work because both heads are tied into both thermostats. One just opens at a higher temp to give more steady temperature.


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That was my thinking but I didn't reply to the post I read that in because like I said, I never tried it. Thanks for clearing it up, I hate to see false information spread

 

[chevyburnout1]

Just bleed the air from the bolt on top of the thermostat housing. Then fill the coolant jug to the top and you'll be set.

 

[onebaddmaxxx]

That won't work because both heads are tied into both thermostats. One just opens at a higher temp to give more steady temperature.


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Actually it does work as i have posted it in the past....It works great and has never failed me yet. you pull the thermostats out. fill the bridge back up with water. You dont need to pull the belt off. Start the truck, it will suck coolant down as it runs. it will eventually steady off. and then which ever side has an issue, will have small little air bubbles coming up from the side. with the thermostat housing cover off, looking straight down you can see easily which way it will come up from. If you want, you can squeeze a piece of cardboard in the housing from front to back and divide the two sides to make it easier.

Have to be creative