Low Coolant, muddy appearance on dipstick

[Jr88fn]

Took my 21 2.0 in for an oil change they said my coolant was low and had suspicious sign of coolant intrusion on dipstick. Scheduled service appt. They pressurized the cooling system to 21 psi, inspected for external leaks in the engine bay and found none. Removed spark plugs and inspected cylinders for coolant intrusion found no evidence. Once engine temp cooled and stabilized they reset pressure tester to 21 psi the system did not lose any pressure. Unclear as to why cooling system was low. The muddy appearance to the dipstick is likely due to an underperforming PCV valve. Said PCV valve was sticking due to carbon collection. Vehicle has not overheated. Any idea on why my coolant is low?

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[ScotM]

When was the last time you checked the coolant? Mine was low from the factory, then two years in, I needed an additional 8 oz. Oil is good, pressure test holds. So I don’t have an explanation for it. First jeep I’ve had to watch the coolant like a hawk. Check your water pump connection to make sure no leak there. I monitor my engine temp with the dash display. I don’t trust the “gauge”. I use the actual temperature

 

[roaniecowpony]

Took my 21 2.0 in for an oil change they said my coolant was low and had suspicious sign of coolant intrusion on dipstick. Scheduled service appt. They pressurized the cooling system to 21 psi, inspected for external leaks in the engine bay and found none. Removed spark plugs and inspected cylinders for coolant intrusion found no evidence. Once engine temp cooled and stabilized they reset pressure tester to 21 psi the system did not lose any pressure. Unclear as to why cooling system was low. The muddy appearance to the dipstick is likely due to an underperforming PCV valve. Said PCV valve was sticking due to carbon collection. Vehicle has not overheated. Any idea on why my coolant is low?

Sounds like a substantial amount of coolant in the oil. You can buy a sample kit with a suction device to pull the sample from dipstick tube. The analysis will determine if there is coolant contamination in the oil.

 

[dstevens]

This has got to be the head gasket - the low coolant and oil contamination is just too much of a conincidence. I've found the best way to diagnose is to use a leak down tester, put 100 psi in each cylinder for about 30 minutes. If there is a head leak then the coolant level will slowly rise. Compression tests, normal leak downs, coolant tests don't find these leaks but the longer pressurization will. I'd like to be wrong on this diagnosis.

 

[PunksJL]

Sounds like a substantial amount of coolant in the oil. You can buy a sample kit with a suction device to pull the sample from dipstick tube. The analysis will determine if there is coolant contamination in the oil.

I would agree with sampling the oil. The analysis will show if there are any water, glycol or potassium in the oil - all signs of coolant in the oil.

 

[Dusty Dude]

This has got to be the head gasket - the low coolant and oil contamination is just too much of a conincidence. I've found the best way to diagnose is to use a leak down tester, put 100 psi in each cylinder for about 30 minutes. If there is a head leak then the coolant level will slowly rise. Compression tests, normal leak downs, coolant tests don't find these leaks but the longer pressurization will. I'd like to be wrong on this diagnosis.

This^^^ I’m wondering if this symptom is a pattern starting to emerge on the 2.0.

21 PSI wont show you squat unless the head gasket is completely gone, which at that point is too late. Under normal operation, the cylinder pressure(and vacuum) will be above that and the leak will be very small, taking a much longer time for the coolant to get where it doesn’t belong.

 

[CorvZ061]

Do you do a lot of short trips? If so that could be the reason for the oil color, not letting the oil get to temp and get the condensation out of the crank case. Coolant could have been low all along. Instead of jumping to conclusions I’d change the oil, top off the coolant and drive it and monitor coolant level.

 

[JEEP4U]

Your going to need a rebuild or a replacement engine in the very near future.

 

[CorvZ061]

This^^^ I’m wondering if this symptom is a pattern starting to emerge on the 2.0.

21 PSI wont show you squat unless the head gasket is completely gone, which at that point is too late. Under normal operation, the cylinder pressure(and vacuum) will be above that and the leak will be very small, taking a much longer time for the coolant to get where it doesn’t belong.

21 psi is a normal pressure to test the cooling system from the radiator or over flow side. If you put 100 psi there you’ll make it to about 40 and start blowing hoses off. They were looking for coolant leaks, not a failed headgasket.

 

[Dusty Dude]

21 psi is a normal pressure to test the cooling system from the radiator or over flow side. If you put 100 psi there you’ll make it to about 40 and start blowing hoses off. They were looking for coolant leaks, not a failed headgasket.

I think you might have misread the comment. The 100 psi is for the cylinder, not the cooling system…. You are looking for how the coolant might be in the oil, not if the coolant is leaking somewhere else. If the head gasket is just starting to fail, not enough volume will go through the leak to lower the radiator pressure enough to detect the leak. The cylinder won’t necessarily show contamination yet, but it will show in the oil first.

 

[CorvZ061]

I think you might have misread the comment. The 100 psi is for the cylinder, not the cooling system…. You are looking for how the coolant might be in the oil, not if the coolant is leaking somewhere else. If the head gasket is just starting to fail, not enough volume will go through the leak to lower the radiator pressure enough to detect the leak. The cylinder won’t necessarily show contamination yet, but it will show in the oil first.

I read it just fine, everyone is jumping to a failed headgasket instead of checking everything else ahead of time. If it’s never been over heated like op claims, it’s hard for me to jump to a head gasket failure.

 

[azjl#3]

Do you do a lot of short trips? If so that could be the reason for the oil color, not letting the oil get to temp and get the condensation out of the crank case. Coolant could have been low all along. Instead of jumping to conclusions I’d change the oil, top off the coolant and drive it and monitor coolant level.

True this, make sure oil hits 210 at least once a week.

My engine oil in a vw golf in alaska, driven maybe 5 miles a day in 30 below, looked like milk shake, and was changed every 2,000 miles.

 

[Dusty Dude]

I read it just fine, everyone is jumping to a failed headgasket instead of checking everything else ahead of time. If it’s never been over heated like op claims, it’s hard for me to jump to a head gasket failure.

I only thought you misread as to where the 100 psi was to be applied. You are 100% correct about not putting 100 PSI directly into the cooling system.


I agree that it is hard to jump to a head gasket right away, but it still needs to be ruled out early. The oil contamination is the biggest clue, whether it be coolant or a PCV issue. It sounded like the mechanic was guessing at the cause. The oil should have been analyzed to get a much more informed analysis before throwing parts at it.

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