First time posting here so pls bare with me. Truck started running rough ... specifically sputtering while accelerating in the 1500rpm area... decided I'd change the plugs and wires, clean out the throttle body etc...when a friend who is a mechanic stopped by. He immediately threw a pressure guage/pump on my radiator and determined I had a leak pressure dropped within the first 20 minutes by about 4psi 18-14... he had me monitor the guage keeping the pressure just above 17 for over 4 hrs trying to determine where the leak was. over the course of the next 3 hours the pressure stabilized somewhat - it would take about 20 minutes to lose 1-2 psi . We never found evidence of coolant leaking.. this was last Wed ... I ran the test again yesterday with same results. His diagnosis - probable head gasket issues... start by doing the routine maintenance I mentioned earlier with plugs etc and add some stop leak to radiator and monitor fluid...truck could run for a week a month or years without an issue..in the meantime watch to see if fluid presents itself... does this sound correct. Have to say this came totally out of the blue..we've kept this regularly maintained although we're nearing 200k on a 2000 truck. Would appreciate any info and advice - thanks
Head gasket??
- Thread starter Perry
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Jon
New member
Few possibilities here. Head gasket being one. If it is a leaking head gasket then you will either have an external leak or internal leaking into the oil galleries (milky dipstick) or into the cylinder itself which will give a lot of steam out the exhaust.
Are you loosing coolant? How much? Running hot? Decrease in MPG's?
Good on you for doing the plugs already. What brand did you use? "Should" be NGK or Denzo. Also attack the fuel system... filter and run some Lucas fuel sys cleaner, maybe new pump (big problem with these getting weak w/o total failure).
Vacuum lines are a huge factor as well.
Is 1500 RPM the only place you get this? How much throttle? How does it perform from idle to red line from a dead stop?
Sorry, tons of factors here. Hope it's not a head gasket.
Are you loosing coolant? How much? Running hot? Decrease in MPG's?
Good on you for doing the plugs already. What brand did you use? "Should" be NGK or Denzo. Also attack the fuel system... filter and run some Lucas fuel sys cleaner, maybe new pump (big problem with these getting weak w/o total failure).
Vacuum lines are a huge factor as well.
Is 1500 RPM the only place you get this? How much throttle? How does it perform from idle to red line from a dead stop?
Sorry, tons of factors here. Hope it's not a head gasket.
Head Gasket?
Hi Jon
thanks for the quick reply
Haven't noticed milked deposit on the dipstick and exhaust doesn't appear to be "steaming" much ( with cold weather its tough to say- although doesn't give any odor of coolant ) Seemed to have lost little less than a quart of coolant over the last week and that was with us forcing the pressure with gauge/pump. I used NGK plugs and am waiting on a fuel filter to arrive. Typically notice "sputtering" when coasting at 45/50mph then as road begins to incline and hit the accelerator ( rpms around 1500 ). Performs fine from dead stop and pretty much any other time as well. it isn't running hot at least yet anyways and have noticed a decrease in mpg to about 14/15
thanks again
P
Hi Jon
thanks for the quick reply
Haven't noticed milked deposit on the dipstick and exhaust doesn't appear to be "steaming" much ( with cold weather its tough to say- although doesn't give any odor of coolant ) Seemed to have lost little less than a quart of coolant over the last week and that was with us forcing the pressure with gauge/pump. I used NGK plugs and am waiting on a fuel filter to arrive. Typically notice "sputtering" when coasting at 45/50mph then as road begins to incline and hit the accelerator ( rpms around 1500 ). Performs fine from dead stop and pretty much any other time as well. it isn't running hot at least yet anyways and have noticed a decrease in mpg to about 14/15
thanks again
P
Jon
New member
Yikes! 14/15 MPGs! That's what I get with 33's and a lift. Any mods? Don't know what to tell you about your magical disappearing water trick except keep looking for an external leak and hope that the stumble and water loss aren't related. It's going some where! Give the trans dipstick a check. Radiator may have an internal failure and blending with the trans fluid to give the "pink milkshake".
What grade fuel are you running? (octane) When you change the filter run the highest oct you can get your hands on (93ish) and throw in a bottle of octane booster and injector cleaner.
Did these both start at the same time? water loss and skipping
What grade fuel are you running? (octane) When you change the filter run the highest oct you can get your hands on (93ish) and throw in a bottle of octane booster and injector cleaner.
Did these both start at the same time? water loss and skipping
chris360hawks
New member
Change fuel filter first. Very unlikely its a head gasket on these motors. Wouldn't be a bad idea to throw a new radiator in there. Also put some new NGK plug wires in.
brian2sun
Elite Member
Well, your cooling system is loosing pressure so your loosing coolant somewhere. If you can't see it on the ground anywhere, then it's either leaking very slow and drying up/evaporating before it hits the ground, or it's being burned up in the engine.
There is one area that is prone to leaks, but if they are small it usually won't make it to the ground That is the water pump, thermostat, and oil cooler area. I had a small leak on the cooling hose coming off the oil cooler and it never leaked on the ground. I found it by getting an extendable mirror and looking for wetness or dried up coolant trails.
If everything looks good with the mirror in that area and you can't see any other obvious leaks from any of the hoses, then it probably is being burned up in the engine since there isn't really anywhere else it can go. Seeing as though the engine is running rough, this is definitely a possibility. Head gaskets aren't a known problem with the 2.7s or 3.4s like they are with the old 3.0s, but EVERY engine is susceptable to a HG failure, especially if the cooling system hasn't been maintained as good as it should have been.
I personally don't think your mechanics methods are great and that is because he neglected to do a compression test and left you wondering if it's a HG. If the compression test shows good #s, a leak-down test should be performed to further rule out a HG. The other reason I don't agree with his advice is because he told you to put Stop Leak in there. That crap is bad stuff and will clog your heater core. If that happens you must take the entire dash apart and replace the core which is about as big of a job as rebuilding your engine. Do yourself a favor and ignore that advice.
There is one area that is prone to leaks, but if they are small it usually won't make it to the ground That is the water pump, thermostat, and oil cooler area. I had a small leak on the cooling hose coming off the oil cooler and it never leaked on the ground. I found it by getting an extendable mirror and looking for wetness or dried up coolant trails.
If everything looks good with the mirror in that area and you can't see any other obvious leaks from any of the hoses, then it probably is being burned up in the engine since there isn't really anywhere else it can go. Seeing as though the engine is running rough, this is definitely a possibility. Head gaskets aren't a known problem with the 2.7s or 3.4s like they are with the old 3.0s, but EVERY engine is susceptable to a HG failure, especially if the cooling system hasn't been maintained as good as it should have been.
I personally don't think your mechanics methods are great and that is because he neglected to do a compression test and left you wondering if it's a HG. If the compression test shows good #s, a leak-down test should be performed to further rule out a HG. The other reason I don't agree with his advice is because he told you to put Stop Leak in there. That crap is bad stuff and will clog your heater core. If that happens you must take the entire dash apart and replace the core which is about as big of a job as rebuilding your engine. Do yourself a favor and ignore that advice.
chris360hawks
New member
If his radiator and tranny fluid are mixing due to the bottom of the radiator leaking could he be losing coolant that way?
