Hello, I have a 97 AWD with 200K miles. I'm the original owner and have taken excellent care of it. The front of the engine has been slightly damp with oil but reciently the leak rapidly got a lot worse, I'm talking big puddle under the van. Also I've had the check engine light with a scanner shows as the result of a lean condition. I'm thinking the check engine light is an intake manifold issue and I'm planning on changing the gasket. Could the big oil leak be from the intake manifold also or what should I be looking for?

Also while I have everything apart what else should I replace? The PS pump is getting noisy so Ill replace it while I'm in there. How about the water pump, should I change it also while everything is appart?

Finally, what about the heater and radiator hoses? They are all original. Can these still be gotten from Ford or a place like NAPA, I'm thinking they should probably all be changed.

Thanks!

 

The oil leak is most probably from the oil pan gasket. At that age, it's brittle and no longer sealing. It's a lot of work to replace; you have to lift the engine up far enough above the front cross member for the pan to clear, and manipulate the pan to pull it out. The pan has baffles in it that catches the pump pickup. There are some pictures here from when I replaced mine:

https://plus.google.com/photos/11555...033?banner=pwa

The oil pan has to be bolted to the transmission, so those bolts have to be tightened together.

I also replaced the intake manifold gaskets, but that was because there was oil and coolant leaks.

This v6 engine has a tendency to shake things apart and cause leaks. If you remove the front dress, you might consider replacing the front cover gasket. I had to replace that as well because of coolant leak. This should be done before the oil pan gasket to make them seal together properly.

The heater hoses are no longer available from Ford, but they may be available from the aftermarket. Again, at this age, it's probably a good idea to replace them. And again, some of those quick-connect couplings may be very difficult to take apart, and a lot of folks cut them off and install standard hose clamps and nipples.

 

Thanks for the info. I should have said the oil is coming from the top of the engine, you can see it is wet with oil starting at just below the intake, although I can't yet tell if it is the manifold or timing chain cover. How difficult is changing the timing cover in an AWD van? I was looking at the shop manual and it sounded like you couldn't change the timing cover gasket with out dropping the oil pan, but it sounds like some of you guys have done this.

My van is really in great shape and has no rust. I have been thinking about doing a complete mechanical rebuild of it but it's sounding like a lack of parts is going to be a big negative.

 

the 1997 4.0 liter engines require a revised upper intake manifold gasket and new "o" rings, I recently did mine, not an easy job, but not difficult either, make sure you mark everything as you disconnect it.

cleaning the top of the aluminum intake manifold was the most time-consuming part, the old gasket was burnt onto it and it took lots of tlc so as not to score/damage the aluminum surface. I used a gasket disolver gel and a plastic scraper, took a few days to dissolve/loosen the worst areas. Do not use metal tools to scrape.

make sure you plug the intake holes so that no old gasket material enters the engine, keep a shop vacuum handy. You need to stay on top of the job, a tool can fall into the engine, a rag, you name it, very dangerous if something falls in there.

 

Jose A, thanks. What kind of gasket sealer did you use?

I went to Ford and got a new H2O pump and a remand PS pump. Went to NAPA for the felpro gaskets.

While I'm "in there" I'm also going to make some new heater hoses by using bulk hose plus some radiator rated plastic "Ts". Anyone done their own heater hoses?

 

Jim, my nephew is a Honda technician and he used a Honda gasket sealer, stuff used at the dealer where he works. I did the dis-assembly, cleaning, and re-assembly, he did the re-gasketing and torquing.

to repair heater hoses I have used aluminum splicers (5/8" diameter) sold at Autozone.

By the way, to remove the 6 upper intake manifold studs, (after removing the 6 nuts), you need a special Torx socket. Best to have a set of those tiny sockets ahead of the dis-assembly.

 

If the leak is from just below the intake, it's the lower intake manifold gasket. There are some pictures at my site of that replacement as well. I cheated by not separating the fuel rail from the lower intake, so did not replace the gasket between them. It's not that bad to do; just be careful not to break anything when pulling off the hoses and wires attached to the manifolds. I broke the little plastic elbow on the PCV valve when I was trying to pull a hose off of it. I disconnected the main wiring harness from the two big connectors under the cowl and left the bundle sitting on the lower intake, and then removed/installed the lower together with all those wires.

Replacing the front cover gasket will disturb the oil pan gasket, so I recommend doing that before the oil pan. You will need a puller for the harmonic damper. I also got a longer M12 fine thread bolt to put in place of the damper bolt for my puller to push against. Once you've pulled the damper, you will have much easier access to the front bolts of the oil pan. So I would leave the front dress off to facilitate working on the oil pan. I also had to drop the front axle, as the pictures showed.

 

Check your PCV first. Sometimes a stuck PCV would allow blow back gas to build up pressure causing oil to be expelled through the valve cover gasket.

 

At least on my car, it was easier to get to the PCV valve AFTER removing the upper intake. It's in the tiny gap between the driver's side valve cover and the upper plenum, and there's very little room to pull the little stub hose off. That's how I broke the plastic elbow.

 

Thanks for all of the info. I'm going to really start taking things apart tomorrow.

 

the PCV valve is easy to check: if it rattles after removing it, it is fine.

 

Just thought I'd let everyone know the project is almost done. The man thing left is replacing the heater hoses. Thanks for your help.

 

There's a special tool to remove the heater hoses from the heater core. I was afraid I was going to damage the core so I replaced the heater valve and hoses back to the engine. If you don't have a heater valve, (my 87 doesn't) Home Depot sells a brass splicer that I used with clamps to replace the bad spot.