So my cooling system is building ALOT of pressure in my 87 3.5 Rangie. I blew a small coolant hose and replaced it on the trail but then the system just kept building pressure real bad, the upper radiator hose gets real real hard. When I relieve the pressure like through the radiator cap the system burps and gurgles for a few minutes. I let the truck run and opened the cap on the top most of the stystem to maybe purge any air but its not working, truck is getting hot now even with dual electric fans on high. No oil in coolant or coolant in the oil, no white smoke so I'm not thinking its a head gasket issue. Any ideas fellas?
Cooling system building pressure
- Thread starter DiscoInferno
- Start date
p m said:
OK..........just wondering how your coming to this conclusion my friend???? Enlighten me please.
Do I see sarcasm here? If so, you are welcome to keep on collecting the opinions until you trash the block. Judging by your truck running progressively hotter, it may not be too far away.
That said... if this indeed is a head gasket failure, this is the first time I've ever heard of that in a 3.5 - thought they were pretty much immune from that.
Now, about how would I come to this conclusion? From painful experience. An engine running in red zone by the gauge will not have coolant pressure enough to blow a hose; the top radiator hose will still be relatively soft to touch. An exhaust gas leak into the cooling system, however, will pressurize it even before the engine is really hot.
Out of 8 times I had to deal with it (on my trucks and others'), there was not a single case of coolant contamination with oil, or vice versa. All but two of them, however, involved head gasket compromized between the coolant passage and the cylinder. The others - cracked block, which is another alternative you may be looking at.
That said... if this indeed is a head gasket failure, this is the first time I've ever heard of that in a 3.5 - thought they were pretty much immune from that.
Now, about how would I come to this conclusion? From painful experience. An engine running in red zone by the gauge will not have coolant pressure enough to blow a hose; the top radiator hose will still be relatively soft to touch. An exhaust gas leak into the cooling system, however, will pressurize it even before the engine is really hot.
Out of 8 times I had to deal with it (on my trucks and others'), there was not a single case of coolant contamination with oil, or vice versa. All but two of them, however, involved head gasket compromized between the coolant passage and the cylinder. The others - cracked block, which is another alternative you may be looking at.
No sarcasm at all, I was just asking for a more detailed reason and you provided me with it, thank you very much. OK, so what would be the best way to test for the head gasket issue?. A cracked block might be pretty difficult to find unless its in a visible place and its large. I'm not sure where to go from here. Thanks again for any advice.
I thought about the radiator and thermostat... but on a recently-cooked truck that ran close to the end of red zone, I was still able to squeeze the top rad hose.
That's a road well-travellled for me. Heater hoses, lower rad hose, expansion tank, heater core...
Try using exhaust gas sniffer on the coolant.
That's a road well-travellled for me. Heater hoses, lower rad hose, expansion tank, heater core...
Try using exhaust gas sniffer on the coolant.
he is right, best guess is the head gaskets. These trucks are known for them, I did one on both Rover V-8s I have owned for any length of time.
ptschram
Well-known member
Springsroverfamily said:
It will almost certainly be much more expensive for your '03 as the OP could probably replace the truck for the cost of an headjob on a 4.4.
:banghead: should have keep my 93 classic Crap just had to fix the expansion tank on my wifes 04 Disco. Im just not having luck with Land Rovers.
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easy enough to tell, with engine running remove coolant tank cap and take a sniff, you will NOT miss the exhaust smell. If you don't want to stick your nose in there, NAPA sells a test kit sniffer that turns the fluid a different color if it picks up exhaust hydrocarbons. Ask me how I know 
another way of testing will be using a coolant pressure test kit, also a cylinder leak down, is your thermostat opening?
have you bled the system properly?
is coolant circulating i/e defective water pump...?
have you bled the system properly?
is coolant circulating i/e defective water pump...?
Either a head gasket or slipped sleeve... I had this happening earlier this year, sent the truck out to get the Hg repaired by a local off-the-books LR tech. After the job was complete, I was still getting the backpressure buildup, so I threw in a bottle of Bar's Stop Leak and it went away. Now.. I just flushed the system according to the repair manual, put in some water wetter and WP lubricant and i have the pressure building up again, although not as much. I think it may be a micro-slip in the stupid non-top hatted cylinder sleeve. Time to throw some more bars in there......