How to: 4.0 OHV Refresh

[97Sandbox]

I'm hoping to bring my recently acquired '00 Sport back to a healthy baseline, and would welcome any suggestions.

The engine runs strong and without any noticeable issues, but has ~260k miles on it. It appears to be seeping oil from the valve covers quite a bit, and there's a very slight coolant leak that looks like it's coming from the water pump.

As a matter of preventative maintenance, I'm considering replacing the following:
- Valve cover & intake manifold gaskets
- Thermostat & gasket
- Water pump and gasket (RockAuto suggests replacing the fan clutch too?)
- Plugs & wires
- Accessory drive belt, tensioner, and idler pulley
- Coolant flush and refill
- Fresh, synthetic 5W-30 and a Motorcraft oil filter
- Motorcraft fuel filter

Is there anything else anyone recommends to bring this engine back into shape?

Oh, and I'm also planning to put fresh Merc ATF in the M5OD and replace the shift lever bushing too. Is it a good idea to go ahead and flush/bleed the clutch?

Thanks for any input!

 

[donalds]

Pcv

 

[C420sailor]

Also keep an ear out for the cam synchronizer. It’s a chirping sound.

 

[97Sandbox]

Pcv

Thanks! I have one laying around that I will be installing, but forgot to mention it.

Also keep an ear out for the cam synchronizer. It’s a chirping sound.

I'll take a look and give a solid listen. Is this something that will be very clearly audible, or should I use my "shop stethoscope" (long flat blade screwdriver held against my ear)?

 

[EB4X]

At 260K I'd jump up to 10W40 oil viscosity .... and throw one of these on there to breathe better....noticeable better throttle response / pep in our hp lacking ohv's : Amazon product ASIN B009DIWHJW

 

[97Sandbox]

At 260K I'd jump up to 10W40 oil viscosity .... and throw one of these on there to breathe better....noticeable better throttle response / pep in our hp lacking ohv's

Thanks! Should've mentioned that I already swapped in the K&N filter I had in my '97. I also have the oem heat shield and larger inlet from a 302 Explorer in this air box.

I already have 5 quarts of 5W30 in the garage -- do you find that 10W40 makes a big difference, or just cheap insurance for a worn engine?

 

[EB4X]

>>> cheap insurance for a worn engine

 

[97Sandbox]

Thanks for all the feedback so far, everyone!

 

[DieselGuy001]

I wouldn't run synthetic oil with that kind of mileage, unless you know for a fact that is all that used in it. If it's leaking now with conventional oil, synthetic will definitely leak. Also pay attention to damper on it. The rubber on the back side likes to come apart.

 

[410Fortune]

replace the oil filter mount O rings
Also EGR big green O ring in the plastic intake manifold
I would consider doing the lower intake manifold and injector O rings while in there as well
the lower intake gaskets simply do not last 260K without developing some leaks
Injectors you might consider adding new /used / flow tested/ matched ones they are under $100
Also new fuel filter!!

If the clutch works good and has no leaks, consider just replacing the driven disc, although with the engine out now would be a great time to upgrade to a SOHC flywheel and SOHC clutch, it is larger, gives better grip, better performance AND much better pedal feel

 

[Pete Deering]

Also keep an ear out for the cam synchronizer. It’s a chirping sound.

N/A

 

[97Sandbox]

replace the oil filter mount O rings
Also EGR big green O ring in the plastic intake manifold
I would consider doing the lower intake manifold and injector O rings while in there as well
the lower intake gaskets simply do not last 260K without developing some leaks
Injectors you might consider adding new /used / flow tested/ matched ones they are under $100
Also new fuel filter!!

If the clutch works good and has no leaks, consider just replacing the driven disc, although with the engine out now would be a great time to upgrade to a SOHC flywheel and SOHC clutch, it is larger, gives better grip, better performance AND much better pedal feel

Thanks for all the great suggestions!

I wouldn't have thought of the filter mount O-ring -- it's on my list now!

Would you happen to have a picture of the EGR O-ring? I remember where one was in my old SOHC intake (I think that one was orange-y rather than green), but I'm new to the OHV 4.0.

Points taken re: intake and injector gaskets. Probably just going to pick up this complete Mahle gasket set and do them all.

Any places you recommend to find flow tested used injectors?

A new Motorcraft filter is already on my workbench and will be getting installed shortly.



I don't actually have the engine out nor do I have plans to take it out (at least until I have a V8 to put back in its place), but I'll keep the SOHC clutch in mind if the current clutch starts to go. Sounds like a solid upgrade!



I've also decided to thoroughly degrease my engine before ordering everything because I just want to 100% identify the leak sources before I dive into replacing gaskets. On closer inspection, I'm afraid my coolant leak may be coming from the timing cover and not the water pump. I already read @fast_dave 's write up on that job and it looks one to approach carefully to say the least!

 

[EB4X]

While you have the LOWER intake manifold off to do it's gaskets REPLACE THE CAM SYNCHRONIZER..(you wont want to deal with that nightmare with intakes in the way later) At 260K there's a decent chance it might've been replaced already ....might want to videotape it with smartphone via braille now to see if it has any shine to it (been replaced) ...otherwise for sure do it....make sure to get the alignment cap...most sellers include that with purchase.

 

[410Fortune]

Mahle kits work fantastic for this engine, I use them all the time

I get my flow matched, 4 hole bosch injectors from Ebay, check seller ratings.

There are two O rings at the oil filter mount

The big green EGR O ring is right where the big stupid EGR metal hose enters the intake manifold, just behind the throttle body drivers side
The replacement O ring is sometimes brown or black
Use PLENTY of vaseline on that O ring when you put the intake back together.......keeps it from tearing

 

[97Sandbox]

There are two O rings at the oil filter mount

Is it one 17 mm one and one 2.482 in one?

 

[410Fortune]

sounds about correct

 

[97Sandbox]

I've finally begun tearing into my Sport this week and it's going pretty well.

After pulling the radiator and fan shroud, I noticed the fan blade has a few cracks, so I'll be ordering a new fan blade and viscous clutch. Removing the upper intake manifold revealed a very disfigured EGR tube o-ring, so that's on my list too.

Next I'll be removing the fuel rail and lower intake manifold. I read in the Mahle gasket kit instructions there are paper gaskets above and below a phenolic spacer under the fuel rail -- should those gaskets be replaced? The gasket kit does not include them and suggests they can be reused if they're in good shape.

I'm also thinking ahead to removing the harmonic balancer. I've read a few anecdotal reports of the factory torque-to-yield bolt being reused without issue, but it doesn't give me warm and fuzzy feelings. Can anyone confirm a replacement bolt part number? I've see both Dorman 926-886 and 926-885 come up in searches, but neither appear to work for the 4.0 according to Dorman's own website.

 

[EB4X]

" I read in the Mahle gasket kit instructions there are paper gaskets above and below a phenolic spacer under the fuel rail -- should those gaskets be replaced?" /\ Always replace any paper gaskets. My 95 did NOT have the phenolic spacer with TWO paper gaskets,...just one paper gasket under fuel rail... BUT this guys 99 (and others) DO! >> SEE 10:11 MARK OF VIDEO >>

This is part of the confusion of how on the various years of 4.0 ohv 2nd gens various kits DIFFER....and various viewpoints....conversation I was just in with 239...and as of that conversation/now I'm dropping my view, which I heard from some, that some years require/recommend paper gasket between upper intake and fuel rail...the pros here say NO on all years, so I'm going to roll with that and disregard prior misinformation I've heard. Although inconvient, I would go with what you FIND when taking YOURS apart, and then order other kit if necessary.....On my '95 KIT I received TWO paper gaskets, therefore manufacturer was under false impression that year had phenolic spacer when it does NOT. This fed into theories by others / and myself about second gasket going between upper intake and fuel rail, which once again is not the case.

 

[97Sandbox]

I should have figured this would get confusing...

Somewhat unsurprisingly, any original paper gaskets and/or phenolic spacer are long gone and a FelPro 90723 was installed under the fuel rail.

There are two gaskets (reddish ones below) in the Mahle kit which look like they would have been installed above and below a spacer:

I'm guessing it's not a good idea to stack new gaskets on an old one. Would it be better to track down an OEM spacer or just buy a new FelPro gasket? Has anyone had good luck with the FelPro gasket?

 

[DP96XLT]

I will be doing the intake manifolds on my 1996 here next week.

I wonder if I will find this "phenolic spacer" on mine when I do it?

I do believe the 90732 "gasket" is a "phenolic spacer" replacement given it's sheer thickness and the aluminum spacer bushings built into it. Personally I would try to get a hold of the same 90732 and then I WOULD use it with both of the paper gaskets included in the gasket kit. It surely wouldn't hurt and would give extra sealing around the ports. I am certain though that Fel-Pro intended the 90732 is intended to be used "by itself". If you can't get a new 90732, I would most certainly clean it off without damaging it and then using it with both spacers. I can't imagine it not sealing if you did that.

When I purchased my materials I purchased the Mahle valvecover kit that included the upper intake gaskets along with both of those other gaskets for use with the spacer. It also has the solid aluminum valve cover gaskets. I also bought the Apex lower intake manifold one-piece aluminum gasket to hopefully make that part of the job go easier.

97SandBox, I am near Milwaukee, give me a shout via PM if you need anything since I am local.