1989 Explorer pushrod V-6

[Anonymous-0]

Just got back from the Ford dealer service dept. Wanted to have the plugs changed and trans flushed.
I memtioned that the check engine light was comming on and they said they would check it out.
I was told the problem was a leakage of coolant that caused CO2 to get into the coolant. Head gasket or head was leaking according to them.
Perhaps a print out of the engine anaylis would have helped me understand.
Anyway would any block sealer solve this problem?
This truck (SUV) has 126,000 easy miles and runs great.

 

[Bob]

There's some part of the "story" missing.

There's no way the 'puter would know if CO2 was getting in the coolant and set a trouble code. There's NO sensor for that!

Closest thing would be if the oxygen sensor in the exhaust was visibly fouled by coolant.

Did they tell you what trouble code was set?

 

[Anonymous-0]

Now, you may have a 1991 Explorer with a 1989 production date, but you don"t have a 1989 Explorer. Or you may have a 1989 Bronco II, which would"ve had a 2.9 liter V-6, which was notorious for cylinder head/head gasket problems. When I was at the Ford dealer from 1996-2000, 2.9 shortblocks were plentiful, but it was hard to find good cylinder heads, or good cores for the Ford Authorized Remanufacturers.

The 4.0 V-6 in the Explorers wasn"t prone to those problems...in fact, it was durn near bulletproof in comparison.

 

[Anonymous-0]

I transposed the numbers the explorer is a 1998. Were these engines subject to leaking heads and gaskets?

 

[Anonymous-0]

The 3.8 V6's, as used in the Mustangs and Taurus and Windstar were subject to a recall for bad head gaskets...we sold a ton of replacement engines from that. But thru 2000, we really didn't see much problem with the 4.0 in the Rangers and Explorers. We regarded the 4.0 as pretty much "bulletproof."

I'd say that the test run by the mechanic was a test of the coolant for CO [carbon MOnoxide], not CO2...and would not generally have shown up during ANY check of the computer...because there's simply no electric/electronic sensor I know of used by the factory that would feed the computer a code for CO in the coolant.