1995 P30 Coolant Leak

[tmw188]

Originally Posted by George Schweikle

For a long shot, check the intake manifold gasket. Our 1999 454 Vortec seemed to use coolant and a drag racing friend said the gasket is usually the culprit for this on Chevy big block engines. I did see some small seepage around the front of the intake manifold, but apparently a lot boiled off. Intake gasket manifold isn't cheap if done by a commercial shop, but I decided to have this done as the repair was outside of my skill level.

So if it is the gasket it could leak into the oil or it could leak to the outside and boil off?

[Soppy]

Gasket could leak coolant into intake , into the oil , outside the engine or any combination , but should not cause overheating if the cooling system is full.

[Soppy]

Originally Posted by 1969SSCamaro

I have a 1995 Georgie Boy with 454 TBI with a coolant leak that I cannot find.

Several weeks ago I had an overheating issue during a steep/long climb in 100 degree weather; temp completely ran away and had to pull-over for about an hour and wait for it to cool down so I could add more water/anti-freeze. The trip was only about 90 miles and I made it home without any issues.For the past year I had been checking the level of the overflow reservoir and never noticed a change in the level, but I suspected a leak had caused the overheating problem. I used a pressure tester to apply 15psi and discovered lower radiator hose was leaking.I Purchased T-bolt clamp as normal clamp would not seal.Did another pressure test and lower hose still leaking.Tightened clamp some more (with a ratchet) and that seemed to fix the issue after another overnight pressure test. Every time I've done an overnight 15psi pressure test it generally seems to only drop 2-4 psi.
Went for another test drive in 95 degree weather today and pushed the temp close to red line. I found it strange that the overflow reservoir did not take on any fluid at all considering how hot the temp was.Total driving time was only about 1 hour.After the engine cooled I checked radiator fluid level and it was about 8 oz low.I think there is still a leak somewhere, but I have checked all potential locations for leaks: block, freeze plugs, heads, intake, water pump, hoses, Etc.There are no obvious puddles of fluid.
I’m now suspecting an internal leak from the intake manifold or head?? I’m running another overnight test.I plan to pull the plugs as I understand a cylinder or manifold leak could result in chalky white residue on the plugs.I also ordered a new radiator cap, but mine appears to be okay: vacuum valve and 15psi pressure valve seem to normal?Any ideas on how to further isolate the leak?I am running out of ideas……….
Thanks,

If the rad is original , chances are its time to replace it . The coolant could be seeping around the tubes and it could be partially plugged causing your overheating problem.

[1969SSCamaro]

Problem solved?? I did a successful 48 hr pressure test, but noticed the coolant was a few oz lower than when I started. Following that I re-pressured the system pulled all the plugs and they looked good; no coolant fluid or smell detected. As I was pulling the plugs and intermittently bumping the upper radiator hose, I say coolant leaking out (where the hose connects to the block)!! That was all on Wednesday evening. Yesterday I installed a new Hayden fan clutch, heater hose and upper radiator hose (lower hose replaced 1-1/2 yrs ago). I fired it up a couple hours ago and it seems okay, but need to take it out for 1 hour drive in the heat. Should be around 90-95 degrees today, so good day to test it out. I'll let ya'll know how it turns out. Thanks again for all the input.

[Lifemember]

Originally Posted by 1969SSCamaro

Problem solved?? I did a successful 48 hr pressure test, but noticed the coolant was a few oz lower than when I started. Following that I re-pressured the system pulled all the plugs and they looked good; no coolant fluid or smell detected. As I was pulling the plugs and intermittently bumping the upper radiator hose, I say coolant leaking out (where the hose connects to the block)!! That was all on Wednesday evening. Yesterday I installed a new Hayden fan clutch, heater hose and upper radiator hose (lower hose replaced 1-1/2 yrs ago). I fired it up a couple hours ago and it seems okay, but need to take it out for 1 hour drive in the heat. Should be around 90-95 degrees today, so good day to test it out. I'll let ya'll know how it turns out. Thanks again for all the input.

[1969SSCamaro]

Last update to close out this issue; thanks very much for all the great input/ideas. Since the last update, I was concerned a slow leak still existed, so used a few Oz. of UV Dye. Went on a couple of short 1 hr drives and seemed to lose a few Oz of coolant. I did another pressure test for 72 hrs and only saw one minor leak on heater hose. Last weekend went out for about 600 mile trip with no coolant loss; YEAH The Hayden fan clutch made an incredible difference and managed the engine temp much better than the stock clutch. It worked so well that the temp rarely got above the normal 210, even under heavy load. Only bad part of the trip was double blowout on right rear, but it was a blessing as I was only going 45 mph. Turns out the concern I had about LT235 tires was real: i should have addressed this when I first bought the coach. The previous OP evidently thought larger tires would improve handling, but having the rear dual tires touching (at the bottom) obviously generated enough heat to blow out the sidewalls. I just had four new LT215/85R16E tires installed. Heading out for planned trip next Wednesday and feel much better. Thanks again!

[Lifemember]

Originally Posted by 1969SSCamaro

Last update to close out this issue; thanks very much for all the great input/ideas. Since the last update, I was concerned a slow leak still existed, so used a few Oz. of UV Dye. Went on a couple of short 1 hr drives and seemed to lose a few Oz of coolant. I did another pressure test for 72 hrs and only saw one minor leak on heater hose. Last weekend went out for about 600 mile trip with no coolant loss; YEAH The Hayden fan clutch made an incredible difference and managed the engine temp much better than the stock clutch. It worked so well that the temp rarely got above the normal 210, even under heavy load. Only bad part of the trip was double blowout on right rear, but it was a blessing as I was only going 45 mph. Turns out the concern I had about LT235 tires was real: i should have addressed this when I first bought the coach. The previous OP evidently thought larger tires would improve handling, but having the rear dual tires touching (at the bottom) obviously generated enough heat to blow out the sidewalls. I just had four new LT215/85R16E tires installed. Heading out for planned trip next Wednesday and feel much better. Thanks again!

I have an older MH and the with 7.50X16 tires. the replacement tire that matched the dia. is 235x85x16 Problem was the 7.50x 16 are 8 inches wide and the 235s are 9+ inches wide. The dia. of the 215 are less then the 7.50 I did not want to change the gear ratio. I did end up with tire kiss. So I ordered 2 inch spacers and problem solved. Picture on post #6
http://www.irv2.com/forums/f120/damo...re-354806.html

[George Schweikle]

Thanks for the closure. Just a comment regarding coolant temperature; I have found the P-30 dashboard temperature gauges to be very inaccurate. In my case on two P-30's, both gauges read low compared to an aftermarket gauge & sender on one and a ScanGauge on the other.

Originally Posted by 1969SSCamaro

Last update to close out this issue; thanks very much for all the great input/ideas. Since the last update, I was concerned a slow leak still existed, so used a few Oz. of UV Dye. Went on a couple of short 1 hr drives and seemed to lose a few Oz of coolant. I did another pressure test for 72 hrs and only saw one minor leak on heater hose. Last weekend went out for about 600 mile trip with no coolant loss; YEAH The Hayden fan clutch made an incredible difference and managed the engine temp much better than the stock clutch. It worked so well that the temp rarely got above the normal 210, even under heavy load. Only bad part of the trip was double blowout on right rear, but it was a blessing as I was only going 45 mph. Turns out the concern I had about LT235 tires was real: i should have addressed this when I first bought the coach. The previous OP evidently thought larger tires would improve handling, but having the rear dual tires touching (at the bottom) obviously generated enough heat to blow out the sidewalls. I just had four new LT215/85R16E tires installed. Heading out for planned trip next Wednesday and feel much better. Thanks again!

[1969SSCamaro]

Lifemember,
I assume you have to install longer lug studs to accommodate the 2" spacer? BTW, I see you are in Bartlesville; I am an Okie as well from Moore and OSU. Transplanted to San Diego.

[1969SSCamaro]

Originally Posted by George Schweikle

Thanks for the closure. Just a comment regarding coolant temperature; I have found the P-30 dashboard temperature gauges to be very inaccurate. In my case on two P-30's, both gauges read low compared to an aftermarket gauge & sender on one and a ScanGauge on the other.

George,
Yes, I don't much care for the idiot gauges and installed my own oil, coolant and transmission temp gauges. At one point I swapped the coolant temp sending unit locations, but swapped them back to original position several weeks ago as I think it controls the electric fan. The coolant gauge I installed is in the intake manifold by the heater hose. The factory gauge is in a hot location next to one of the block cylinders, so it is always hotter than the intake manifold.

[kennyrodgers]

Hi Greg,
Glad you got it sorted bud.
I take it you have a 4L80E transmission, if so can you tell me where you ran the temp gauge from ?
Thanks in advance,
Pete.

[Lifemember]

Originally Posted by 1969SSCamaro

Lifemember,
I assume you have to install longer lug studs to accommodate the 2" spacer? BTW, I see you are in Bartlesville; I am an Okie as well from Moore and OSU. Transplanted to San Diego.

No, I did not need to alter the studs. This is the spacer on the inside tire.

I am transplanted from the east cost

[1969SSCamaro]

Originally Posted by kennyrodgers

Hi Greg,
Glad you got it sorted bud.
I take it you have a 4L80E transmission, if so can you tell me where you ran the temp gauge from ?
Thanks in advance,
Pete.

Yes, I do have 480 tranny. I installed a new/deep pan with cooling fins (actually tubes for airflow) and it had a fitting to install a temp gauge.

[1969SSCamaro]

Originally Posted by Lifemember

No, I did not need to alter the studs. This is the spacer on the inside tire.

I am transplanted from the east cost

Attachment 181729

Thanks for the pic; now I understand. Live and learn; wish I would have done the same thing when I first got the MH!!!