Today I got the results of my first UOA on the 99 Surburban 7.4 we bought last year to tow the GF's horses around ( link ). One year on the oil, 1500 miles.
As you can see from the UOA, there's a coolant leak. I'm hoping this is one of the engines that has intake gasket problems because I really don't want this to be the head gaskets. I may give it a compression check this weekend if I can find the time (although I'm not looking forward to trying to get at the rear spark plugs) to verify.
It was visibly loosing coolant for a little while, but it was after I'd drained and replaced most of the coolant when I replaced the thermostat, so I figured it was just burping all the air out of the system. The coolant level has not fluctuated for several months now (probably the last 100-200 miles). So, it's not putting a huge amount into the oil at this point.
I had a few questions:
1) If it is the head gaskets, will a compression check definitely show it?
2) If it's not the head gaskets, is it likely the intake gasket or could it be something else? What can I really do to figure out what the problem is?
3) How involved is the intake gasket replacement? Is it a DIY'er friendly task or am I better off taking it to a mechanic?
4) Do I need to treat this as a "don't drive the car except to the mechanic to get it fixed" problem? The GF was planning on towing her horses to a show next weekend. It would entail about 100 miles of driving, mostly towing a two horse trailer, including some high load driving up a grade. I'm not too thrilled about that prospect but OTOH I'm not sure an extra 100 miles are going to hurt anything. Who knows how long this has been going on, anyway.
As you can see from the UOA, there's a coolant leak. I'm hoping this is one of the engines that has intake gasket problems because I really don't want this to be the head gaskets. I may give it a compression check this weekend if I can find the time (although I'm not looking forward to trying to get at the rear spark plugs) to verify.
It was visibly loosing coolant for a little while, but it was after I'd drained and replaced most of the coolant when I replaced the thermostat, so I figured it was just burping all the air out of the system. The coolant level has not fluctuated for several months now (probably the last 100-200 miles). So, it's not putting a huge amount into the oil at this point.
I had a few questions:
1) If it is the head gaskets, will a compression check definitely show it?
2) If it's not the head gaskets, is it likely the intake gasket or could it be something else? What can I really do to figure out what the problem is?
3) How involved is the intake gasket replacement? Is it a DIY'er friendly task or am I better off taking it to a mechanic?
4) Do I need to treat this as a "don't drive the car except to the mechanic to get it fixed" problem? The GF was planning on towing her horses to a show next weekend. It would entail about 100 miles of driving, mostly towing a two horse trailer, including some high load driving up a grade. I'm not too thrilled about that prospect but OTOH I'm not sure an extra 100 miles are going to hurt anything. Who knows how long this has been going on, anyway.