Head replace or replace the motor?

[pathwayus]

I just picked up a 92 explorer that has very little rust on it. It show that it has around 88000 but am going to guess that's 188000. The antifreeze and oil have mixed in it so am guess the head's are cracked. This is dew to the fact that the water pump is leaking like crazy so am guessing that it over heated. So it was left on the side of the road and towed in and the place i picked it up for got a clean title on it. I've never replaced the head on anything before i've watched a few videos on it and do some research. I may still just replace the hole motor. I would welcome any input that anyone may have on doing this.

 

[timtimtimajim]

I just helped a buddy replace the heads on his 89 F-150 after he had over heated it. It was a pain in the butt replacing them and it was leaking antifreeze when we finished and would not start.
So personally I would say it would be easier just to swap in a new motor, especially on an Explorer. It might cost a bit more, but in the end you would be less likely to screw something up.

 

[natenkiki2004]

If you can get a sound motor, that might be a good option.

HOWEVER, unless you get another Explorer and see it run, perform compression tests and check the oil pressure... you won't know the condition of the replacement motor you get and you can end up with more problems.

Fixing what you have means you know exactly what you have internally and know the limitations, shortcomings or benefits of your motor. Replacing heads ain't cheap nor is it easy but once done, you could easily double that mileage.


But let's not get ahead of ourselves. The water pump is leaking, that could be good. It might just be the timing cover leaking into the pan due to a severe gasket issue. It's designed not to leak into the pan but it's possible. Another high possibility is the lower intake gasket, that thing loves to leak at the coolant passages going into the head.

First things first, get the oil out of the engine and some fresh (and cheap) oil into it. Perform a leakdown test and maybe a compression test as well. The same hose will allow you to hook an air compressor to the cylinder and see if it holds pressure. In the process of doing a leakdown test, you can hear/see where the air is escaping if the head or gasket is compromised.

For example, if you hear hissing in the intake, your intake valve is buggered on that cylinder. If you see bubbles in the radiator, the head or gasket is buggered. If you take the oil fill cap off and hear hissing in there, your rings are worn. If you hear hissing in the exhaust, that's the exhaust valve. It's a very definitive test.

If the test is inconclusive or you hear no hissing, pressurize the coolant system and see where the leak comes from.

You will need to get some tools to do these tests but they're not that expensive and are the first steps to properly diagnosing the issue and not wasting money.

 

[pathwayus]

What I do know is before anything could be done the water pump leak has to be fixed, the leak is bad. I have also noted lot of white smoke form the tail pipe the history of the motor is unknown. I have priced new heads and the head bolts and gasket kits which would be more then i payed for the truck. I have also priced the motor at pull a part there cheep with 30 day warranty. I have also priced the head there but don't really like the idea of used heads.

 

[2stroke]

If you decide to go with a used motor, realize there are some things you should replace on it, else you are wasting your time. The pan gasket and water pump are a bare minimum. The front and rear seals and timing cover are a good idea. Intake gaskets and valve covers can be done just as easily with the engine in, so I wouldn't worry about those. Also realize that 91 and 92 engines had a poor head casting that is prone to cracks. 93 and 94 have an improved design that is less prone to cracking. An engine can run just fine with a cracked head, just realize that new heads are the name of the game when you blow a head gasket on these engines. Aftermarket heads are the best way to go IMO. With only 190 k on the engine, I would replace the heads and head gaskets and keep running it.

 

[pathwayus]

Am i wrong in thinking that some of the 2ng explorer 4.0 motor will also work just half to change the mounts out right? Seem like i read that some where.

The one thing i do like about doing a head change is new gaskets other then the oil pan.

 

[Wolfie_85]

Remanned engines are around $1,800 to $1,900. Having a shop do a head gasket is over a grand. Mine ended up being $1,600. I didn't do it myself, because I had to garage, and it was the dead of winter. Just something to think about. Most of the remanned engines come with the heads attatched, but you provide pretty much everything else (oil pan and gasket, timing cover and gasket, valve covers and gaskets, upper and lower intakes and gaskets, water pump, starter, etc.)

Used engine is a good option (as it's usually complete), make sure it checks out, and warrenty is preferred. My best piece of advice is to understand getting and keeping a vehicle of this age means potentially (almost certainly) more than it's worth on repairs and maintenance. And check the tranny fluid for signs of burning and make sure it's level is good. The A4LD does NOT respond well to neglect. Putting that much into the engine while you might have a bad tranny is an expensive mistake. Yours is probably fine, but check it out, if you haven't or aren't sure.

 

[pathwayus]

I did check the transmission today there was leak coming for the new rad because it was missing a oil ring for the cooler lines but that fixed now. Thanks for the input so far every one