4.0 pushrod coolant leak | Page 2 | Ford Explorer Forums - Serious Explorations

  • Register Today It's free!

4.0 pushrod coolant leak

OLD THREAD .....DPDISXR4Ti was inquiring about swapping out a 2.9 for a 4.0 and coolant / intake setups.
(P.S. I had another 4.0 ohv (Ranger) which I slightly overheated and didn't harm / affect heads or h. gaskets what so ever.... sold it running great just shy of 258,000 without ever needing to take engine apart for anything - only sold it to get my current 4.0 ohv 4WD....these engines are not cracking heads left and right....only when significantly overheated)
 



Join the Elite Explorers for $20 each year.
Elite Explorer members see no advertisements, no banner ads, no double underlined links,.
Add an avatar, upload photo attachments, and more!
.





I don't currently have a vehicle with the 4.0 OHV engine, but rather it's predecessor, the 2.9, which does not have coolant routed through the intake manifold. I'm considering a 4L swap, but in the interest of plumbing simplification and reliability, I'd want to continue with a "dry" intake. I can't find anywhere that this has been discussed. Is it possible? Has anyone actually done it?
@DPDISXR4Ti

This is a re-hash of what you already know, but for anyone else; The 4.0 OHV lower aluminum intake takes the thermostat on the front, and uses the front two water passages on the lower aluminum intake to interconnect with the heads. The two rear water passages are blocked off.

This/Yours is the first question I've ever read concerning this "backwards" swap to putting a 2.9 lower intake on a 4.0

Although we have a huge braintrust here, the only guys I think of that can possibly help you out are over at The Ranger Station website.

They do all sorts of crazy mods to the Cologne Germany OHV V-6, the 3.0 and 4.0 AND they do have a 2.9 Forum (LINK BELOW).

LINK
: 2.9 Liter Forum

Hope that helps & good luck!

P9050064.JPG


P9050065.JPG


P9180210.JPG
 






@DPDISXR4Ti
Although we have a huge braintrust here, the only guys I think of that can possibly help you out are over at The Ranger Station website.
Yep, already on there, but thanks. I'm finding it's probably best to just stick with the 4.0 stuff overall and not get too crazy creating a FrankenCologne.
 






@DPDISXR4Ti

Yeah, a lot have water has gone under the bridge since the introduction of these engines, and if you haven't seen a write-up or YouTube video on the subject, there's probably a reason ;)

You know, for sheets & giggles, you could always try and contact Tom Moran @ Moran Motorsports | Professional Drag Racing Products and Services and ask him if it's been tried.

Let us know if you find anything out!
 






Have done some reading about the 4.0 pushrod engine leaking coolant here and there. I have that problem with the 4.0 in my 98 Ranger. Coolant disappearing, oil was milky plus white exhaust at initial startup/warm up. So I removed the plenum, lower intake, front engine cover and found several places where the coolant was getting into the engine oil. Reassembled with new Felpro gaskets. No more coolant in the oil. BUT....I still had coolant disappearing, white exhaust on start up/warm up. So I parked the truck and next day when the engine was cooled down, pulled all the plugs and looked for any signs of coolant on them, None found. Used a bore scope, looked at each cylinder, nothing unusual, no coolant in any cylinders. All the plugs looked nice and clean. So I rented a coolant tester, the kind what detects exhaust in the coolant. Did that test on two separate occasions, no exhaust in the coolant either time. Then I did a coolant system pressure test at 15 pounds and started finding some slow leaks on hose connections, lower radiator core...so quit that before I blew out the radiator. Never find any coolant on the floor under the truck so gave up on the coolant pressure test. Still loosing coolant and white exhaust on start up/warm up. Disappears after the engine is warmed up. I had done a compression test earlier with inconclusive results but decided to do a cylinder leak down test. Pulled all the plugs, tested each cylinder at top dead center with 80 pounds of air. Watched for bubbles in the radiator. Every cylinder tested 80/80! So no blown head gasket or combustion chamber problem which explains why all the spark plugs looked good and no coolant in the cylinders. So...now I am thinking possibly a crack in a cylinder head between the intake manifold and intake valve somewhere and am planning on pulling the plenum and pressurizing each intake passage. Any ideas or does anyone see anything I might be missing here?
I have the same mystery coolant disappearance on my 95 4.0 ohm, none in the oil, some fumes at start up but goes away when warm, no smell, no drips…the coolant just disappears. I thought head gasket too, but again no smell, no constant cloud behind me and no evidence of coolant in oil. Did you ever find any leak point?
 






Do you have any spark plugs that keep fouling out? If so, you probably have a cracked cylinder head or heads. I have a 2000 Ranger with the 4.0 ohv & it would routinely foul out one spark plug & loose coolant that I could not find where it was going. After dealing with the fouling spark plug issue for one year, I finally pulled the cylinder heads & found both had a hairline crack in each one.
 






Do you have any spark plugs that keep fouling out? If so, you probably have a cracked cylinder head or heads. I have a 2000 Ranger with the 4.0 ohv & it would routinely foul out one spark plug & loose coolant that I could not find where it was going. After dealing with the fouling spark plug issue for one year, I finally pulled the cylinder heads & found both had a hairline crack in each one.
How many miles at the time roughly?
 






IIRC it was approximately 135K miles.
 






IIRC it was approximately 135K miles.
/\ Overheated by previous owner.... .......or yourself ?
 






IIRC it was approximately 135K miles.
/\ Overheated by previous owner.... .......or yourself ?
It must have been by the PO, I never overheated it.
 












I would pull the plugs & check the condition of the spark plugs & do a compression test while the plugs are out.
 






FYI coolant in the combustion chamber will white wash your plug tips… usually with a 4.0 cyl 1-2 4-5 will have a nice tan color where as 3 and 6 will be white washed, no tan, no brown, no carbon buildup on electrode…’just washed from coolant in chamber

Lower intake and head gaskets need attention after 25+ years on these engines

Don’t buy cheap heads! We did and a month later I replaced all 12
Valve seals and 2 broken springs
 






FYI coolant in the combustion chamber will white wash your plug tips… usually with a 4.0 cyl 1-2 4-5 will have a nice tan color where as 3 and 6 will be white washed, no tan, no brown, no carbon buildup on electrode…’just washed from coolant in chamber

Lower intake and head gaskets need attention after 25+ years on these engines

Don’t buy cheap heads! We did and a month later I replaced all 12
Valve seals and 2 broken springs
You’re right by age alone I need to do some work, I just hope I can make it until summer, too cold too snowy outside to rip this apart in the driveway
 






Back
Top