ISL question, faint anti freeze odor

[smlranger]

I had posted some weeks ago about my suspicious oil sample that showed evidence of antifreeze in my oil (high sodium and potassium levels). Local Cummins shop who has serviced my coach suggested we change oil, put on a few miles and get another sample. I am not visibly losing coolant but Cummins did suggest a remote possibility of an EGR cooler leak. They did put a can of Zerex stop leak in the coolant.

So, returning from a 800 mile trip and coolant level in sight glass on reservoir is right where it was before we started. However, when the coach is hot, I can barely notice that characteristic hot coolant smell near the engine access hatch. No smell if I 'sniff' around the radiator outside and I see absolutely no evidence of any leaks.

So, can you get this kind of smell if you have a head gasket or intake manifold gasket leak? Cummins really dismissed the idea of any type of gasket leak since I have no running issues.

At any rate, I will be pulling another oil sample soon and hope to get a better report.

[2NewRVers]

Originally Posted by smlranger

I had posted some weeks ago about my suspicious oil sample that showed evidence of antifreeze in my oil (high sodium and potassium levels). Local Cummins shop who has serviced my coach suggested we change oil, put on a few miles and get another sample. I am not visibly losing coolant but Cummins did suggest a remote possibility of an EGR cooler leak. They did put a can of Zerex stop leak in the coolant. So, returning from a 800 mile trip and coolant level in sight glass on reservoir is right where it was before we started. However, when the coach is hot, I can barely notice that characteristic hot coolant smell near the engine access hatch. No smell if I 'sniff' around the radiator outside and I see absolutely no evidence of any leaks. So, can you get this kind of smell if you have a head gasket or intake manifold gasket leak? Cummins really dismissed the idea of any type of gasket leak since I have no running issues. At any rate, I will be pulling another oil sample soon and hope to get a better report.

Good luck, keep us posted.

[spike45]

Originally Posted by smlranger

I had posted some weeks ago about my suspicious oil sample that showed evidence of antifreeze in my oil (high sodium and potassium levels). Local Cummins shop who has serviced my coach suggested we change oil, put on a few miles and get another sample. I am not visibly losing coolant but Cummins did suggest a remote possibility of an EGR cooler leak. They did put a can of Zerex stop leak in the coolant.

So, returning from a 800 mile trip and coolant level in sight glass on reservoir is right where it was before we started. However, when the coach is hot, I can barely notice that characteristic hot coolant smell near the engine access hatch. No smell if I 'sniff' around the radiator outside and I see absolutely no evidence of any leaks.

So, can you get this kind of smell if you have a head gasket or intake manifold gasket leak? Cummins really dismissed the idea of any type of gasket leak since I have no running issues.

At any rate, I will be pulling another oil sample soon and hope to get a better report.

Slow leaks can be found by looking for a light colored trace deposit. The additives in the coolant make up the trace. The elevated sodium and potassium are key indicators of engine coolant in the oil as both elements are part of the additive package. If you care to, send my your coolant analysis or post it so I can look at it. You will have to look in the area of the EGR cooler to see if there is an external leak. Most of the EGR cooler failures result in internal cracking of the top seam of the cooler releasing small amounts of coolant into the EGR gas stream. That enters the engine through the intake air stream mixing with the EGR gases. Internal leaks are not spotted externally. You may need to look in the area of the water pump weep hole. It is a small hole that near the point where the pump mounts into the front accessory drive. The pump is gear driven. Check to see if the weep hole is plugged. It is supposed to be open so that any small leakage can escape to the outside instead of enter the front gear drive. The drive gear has an oil seal to keep lubricant from leaking into around the shaft. If the hole is plugged AND you have any coolant leak, coolant can push past the oil seal and get into the engine. The oil seal is designed to keep oil IN not prevent external fluids from entering. The hole could be plugged by small oil seepage from a failing shaft seal. The seepage combines with dust and can plug the hole. This is not a common scenario but it is not unheard of either.

[smlranger]

Originally Posted by spike45

Slow leaks can be found by looking for a light colored trace deposit. The additives in the coolant make up the trace. The elevated sodium and potassium are key indicators of engine coolant in the oil as both elements are part of the additive package. If you care to, send my your coolant analysis or post it so I can look at it. You will have to look in the area of the EGR cooler to see if there is an external leak. Most of the EGR cooler failures result in internal cracking of the top seam of the cooler releasing small amounts of coolant into the EGR gas stream. That enters the engine through the intake air stream mixing with the EGR gases. Internal leaks are not spotted externally. You may need to look in the area of the water pump weep hole. It is a small hole that near the point where the pump mounts into the front accessory drive. The pump is gear driven. Check to see if the weep hole is plugged. It is supposed to be open so that any small leakage can escape to the outside instead of enter the front gear drive. The drive gear has an oil seal to keep lubricant from leaking into around the shaft. If the hole is plugged AND you have any coolant leak, coolant can push past the oil seal and get into the engine. The oil seal is designed to keep oil IN not prevent external fluids from entering. The hole could be plugged by small oil seepage from a failing shaft seal. The seepage combines with dust and can plug the hole. This is not a common scenario but it is not unheard of either.

Spike, thanks for the suggestions. I pulled the oil sample yesterday and will be sending it to the lab tomorrow. I will surely post the results for you to see. I will check the weep hole.

The Cummins folks believe the most likely culprit is the EGR cooler and plan to pull it for pressure testing if this oil sample reveals evidence of coolant contamination.

I've done some research on EGR cooler leaks and at least one vendor called Bullet Proof Diesel claims to have a better cooler than the OEM Cummins cooler. If I need a new one, do you have any suggestions for replacements?

[smlranger]

Gary, I got the results from the oil sample I recently pulled. Basically, they say there are no concerns.....both the K and Na levels in this sample are much lower than my previous sample; Na 22, K 13 in this sample compared to Na 45 and K 60 in previous sample. They did note water >1% in the sample. I had been parked the night before pulling this sample in very cold weather (temps down to 14F) and only drove the coach about 30 miles to home before pulling this sample. I wonder if I had some condensation and the 30 mile drive was not sufficient to remove any condensation that may have been in the engine??

They recommend pulling another sample in about 3,000 miles to check any trends. I have attached the report for you to look at.

It is interesting that the local Cummins Atlantic facility uses Carter CAT's lab for their samples. I dropped the sample off today at noon and they called me with the results at 3:00PM, $18 for the analysis.

[spike45]

Originally Posted by smlranger

Gary, I got the results from the oil sample I recently pulled. Basically, they say there are no concerns.....both the K and Na levels in this sample are much lower than my previous sample; Na 22, K 13 in this sample compared to Na 45 and K 60 in previous sample. They did note water >1% in the sample. I had been parked the night before pulling this sample in very cold weather (temps down to 14F) and only drove the coach about 30 miles to home before pulling this sample. I wonder if I had some condensation and the 30 mile drive was not sufficient to remove any condensation that may have been in the engine??

They recommend pulling another sample in about 3,000 miles to check any trends. I have attached the report for you to look at.

It is interesting that the local Cummins Atlantic facility uses Carter CAT's lab for their samples. I dropped the sample off today at noon and they called me with the results at 3:00PM, $18 for the analysis.

Actually, it is not unheard of that Cummins distributors use the local CAT dealer oil lab. I would not be upset about the water content given that the temps are quite low and the oil temperature may not be above the boiling point of water. When the ambient temps are higher and you run hard enough, the lube oil temperature will run about 40 degrees above the jacket water outlet temperature. I extreme cold operation, the thermostats may not open fully. Cooling is more by cold air blowing on the cylinder block than radiator cooling. You, no doubt, have seen the winter front on some on-highway trucks as well as putting cardboard in front of the radiator on smaller vehicles. Keep cold air from blowing on the engine and preventing lower temperatures that the thermostat cannot prevent even if it stays closed completely.