99 Suburban Coolant leaks
#1
CF Beginner
Thread Starter
99 Suburban Coolant leaks
New poster on the forum, but have successfully completed a dozen repairs on my suburban. Great info here. I have read too many threads on this issue and was becoming confused, so I started my own. I need help with the diagnosis and some other questions. My garage is well equipped and I know what repairs I can handle and those I need to farm out to a pro. Here we go.
99' K1500 5.7, 112,000 miles, well maintained.
- Coolant; Noticed a loss of coolant a week ago and some fluctuations in the temperature gage. It was low so I topped off and burped with DexCool and replenished the reservoir. Have had to replace and top off almost daily with DexCool. I am getting some bubbles coming up in the radiator cap. Still pink, but looks a little 'brownie'. I have NO external leaks or visible drips anywhere. When warm temp is 170-180. Seems low?? Pump is fine and treated in 2012, with no leaks.
- Engine; Runs great, gas mileage is good considering. (Consistent) No codes or other issues. I pulled all the spark plugs and they all look good. Clean, dry and the right color, they were new in 2012.
- Heater; Still blasting heat front and back system.
- Oil; Oil is clean (1500 miles since changed) BUT, I have the white frothy deposits all over the cap and in the fill tube. Cleaned them good to double check and its back there the next day. Also appears to be wet with water from the coolant mix.
- Exhaust; I have a pretty good cloud of white fog coming out with the regular exhaust. Can't say anything for the smell or taste, but my understanding is Dexcool doesn't do either.
So, which leak do I have? I think its the intake manifold....
Could I have more than one leak, but need professional opinion from forum?
I appreciate your assistance so I can see if I can handle the repair. Need to get this fixed pretty quickly, so I can tow my boat.....
I will respond quickly with any other questions and to see what other easy maintenance items I can replace along the way.
99' K1500 5.7, 112,000 miles, well maintained.
- Coolant; Noticed a loss of coolant a week ago and some fluctuations in the temperature gage. It was low so I topped off and burped with DexCool and replenished the reservoir. Have had to replace and top off almost daily with DexCool. I am getting some bubbles coming up in the radiator cap. Still pink, but looks a little 'brownie'. I have NO external leaks or visible drips anywhere. When warm temp is 170-180. Seems low?? Pump is fine and treated in 2012, with no leaks.
- Engine; Runs great, gas mileage is good considering. (Consistent) No codes or other issues. I pulled all the spark plugs and they all look good. Clean, dry and the right color, they were new in 2012.
- Heater; Still blasting heat front and back system.
- Oil; Oil is clean (1500 miles since changed) BUT, I have the white frothy deposits all over the cap and in the fill tube. Cleaned them good to double check and its back there the next day. Also appears to be wet with water from the coolant mix.
- Exhaust; I have a pretty good cloud of white fog coming out with the regular exhaust. Can't say anything for the smell or taste, but my understanding is Dexcool doesn't do either.
So, which leak do I have? I think its the intake manifold....
Could I have more than one leak, but need professional opinion from forum?
I appreciate your assistance so I can see if I can handle the repair. Need to get this fixed pretty quickly, so I can tow my boat.....
I will respond quickly with any other questions and to see what other easy maintenance items I can replace along the way.
#2
CF Beginner
Thread Starter
One more thing....
I was checking the oil cold after sitting. I ran it today to recharge the A/C and then checked the dip stick. I have chocolate milk on the dip stick.... ugh.
I was checking the oil cold after sitting. I ran it today to recharge the A/C and then checked the dip stick. I have chocolate milk on the dip stick.... ugh.
#4
CF Beginner
Thread Starter
1) Intake manifold gasket. Roughly $550 for full kit repair, plus extras like temp sensor, new bolt sets, distributor and rotar. $625 in total estimate.
2) Head gasket. Rougly $2200 for full kit repair, plus extras and shop fee for clean, resurface and pressure check heads. Roughly $2600.
All the other things being pretty good, he did not think it was a cracked head. I am frugal and won't spend that kind of money and secondly I do not like surprises. I really need to find out what this is before i check back with him and/or seek out a second opinion.
Let me know........
#5
You can rent the pressure tester at a lot of autoparts stores. I had the same problem about a month ago on a fresh rebuilt motor. Pressure test showed that I was leaking coolant at a heater hose down by the firewall.
That being said, yours sounds like it would be an intake gasket. With all the work required to get to the intake, you might as well do the heads at the same time. I don't know if the prices you quoted are good or not, sound real high to me. But get a second estimate for sure.
That being said, yours sounds like it would be an intake gasket. With all the work required to get to the intake, you might as well do the heads at the same time. I don't know if the prices you quoted are good or not, sound real high to me. But get a second estimate for sure.
#6
CF Beginner
Thread Starter
You can rent the pressure tester at a lot of autoparts stores. I had the same problem about a month ago on a fresh rebuilt motor. Pressure test showed that I was leaking coolant at a heater hose down by the firewall.
That being said, yours sounds like it would be an intake gasket. With all the work required to get to the intake, you might as well do the heads at the same time. I don't know if the prices you quoted are good or not, sound real high to me. But get a second estimate for sure.
That being said, yours sounds like it would be an intake gasket. With all the work required to get to the intake, you might as well do the heads at the same time. I don't know if the prices you quoted are good or not, sound real high to me. But get a second estimate for sure.
Little disappointed I didn't get more response from the senior members of the forum so I can get it to the right shop.
#7
Super Moderator
kevinkpk drew the line on the repair, I agree with him, most of us usually do. Now it's up to you to just do the Intake, or be sure about it, and go down to the Head Gaskets. With that, at least you'd be able to check the Heads for a crack.
Last edited by SWHouston; April 17th, 2013 at 11:07 AM.
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#8
I just had the same issue with my 1999 Subruban 5.7 2wd with 200k. Oil turned to Hershey's chocolate milk! Most common issue seems to be the intake manifold gasket. However, we decided in for a penny in for a pound and removed heads. Magnaflux showed both heads were cracked. So while in that far we did the oil pan gasket, timing gears, chain gasket. So now its new from the block up! Hoping for 300k if the original tranny will hold out.
#9
CF Beginner
Thread Starter
In the past 24 hrs, your thread has had over 200 views, many of those by the tenured members of this forum. Given my experience with their opinions, had they had anything to add, you would have seen it, and there's no use in just repeating a recommendation over and over.
kevinkpk drew the line on the repair, I agree with him, most of us usually do. Now it's up to you to just do the Intake, or be sure about it, and go down to the Head Gaskets. With that, at least you'd be able to check the Heads for a crack.
kevinkpk drew the line on the repair, I agree with him, most of us usually do. Now it's up to you to just do the Intake, or be sure about it, and go down to the Head Gaskets. With that, at least you'd be able to check the Heads for a crack.
I took it to the dealer and will them work it out. I will give them the AMX when its all settled.
#10
milky oil points to head gaskets/cracks and to do head gaskets you have to remove the intake anyway...yea it may be the shotgun approach but it'd cover the bases....and i'll be surprised if it isn't head related