4.0 SOHC Rear Timing Chain Tensioner Oil Leak

[2000StreetRod]

It's a risk

It's a risk to drive it since you plan to get it repaired. If the guide jams in the wrong position the chain could slip. A tow would cost $75 or so and that's the safest approach. However, (and don't blame me if I'm wrong) if it didn't jam at engine start and idle you'll probably make it to the shop. If you decide to drive don't rapidly accelerate or decelerate (use light throttle and braking) and keep the engine speed low (let the transmission upshift in drive and back up slowly in reverse). If you have hills don't downshift for engine braking.

 

[krispy97xlt]

An update:

I convinced the shop that was doing the work to include a tow from my garage to their shop.

They picked up the truck on Saturday and began working on in Monday AM. By Tuesday AM they called to tell me that the engine was out and they had began ordering parts. They also informed me that they wouldn't be able to meet their price quote of $1600 dollars using Ford OEM parts. I instructed them to go ahead and spend the extra on genuine Ford components.

Later that afternoon I stopped by unannounced to check on the progress of the truck I snapped some pictures of what I saw very quickly.

^Rear guide and chains replaced

^Front timing cover removed

^Drivers side valve cover off

^Evidence of ford parts being used.

 

[krispy97xlt]

^The engine bay 1

^Engine bay 2


So with all the pictures posted can you spot any abnormalities?

*Of note. I did spot the proper ford tools for timing these engines in the shop.

 

[2000StreetRod]

I'm glad you got the tow

I notice that the boot/bellows on the steering shaft is split but not as bad as mine. Ford doesn't sell the boot separately and it can only be obtained from Ford by puchasing the entire lower shaft assembly. I haven't been able to find a suitable substitute. The assembly costs about $300 (list price) and in my opinion it's worth that to replace.

I saw the timing tool kit and the broken rear guide in one of the photos. Make sure they check the oil pickup screen for trapped guide particles.

It looks like the engine still has the original primary timing chain tensioner. The newer design is greatly improved (more leaves in the spring and a wider base). Definitely worth replacing even if not broken which I can't tell from the photos.

I can't see the balance shaft tensioner to see if it is broken. The block girdle (upper oil pan) will have to be removed in order to properly replace the tensioner.

I can't see if the left (driver side) guide assembly is broken. It has a "finger" that typically is the first thing to break.

I hope everything goes well with the engine assembly and restart.

 

[krispy97xlt]

Is the seal that goes from the front of the crank through the front timing cover normally replaced when the timing cover is pulled?

I am just thinking that since I went to the trouble of replacing the rear main, I should also replace this one too.

Also, can you think of suitable torture to put the broken guides through as payback for costing me this $?

 

[2000StreetRod]

timing cover seal

I didn't replace my timing cover seal but was very careful to reinstall the cover in the same place as original. I was lucky and had no leaks. The safest method is to replace the seal. Some members have posted they had oil leaks thru the keyway on the crankshaft and seal it when installing the harmonic balancer. I didn't seal it and had no leaks.

 

[krispy97xlt]

Well I am currently in the process of picking my Sport Trac back up.

Total damage done: $1820

Parts 902.77
Labor 854.04
Tax 63.19

Replaced spark plugs with motorcraft double platinum. Replaced rear main seal.

All parts used on the timing chain replacement were ford oem parts.

 

[2000StreetRod]

reasonable labor cost

The labor cost was extremely reasonable. The shop probably made some money on the parts to offset the labor. Your engine should last another 150K miles!

 

[krispy97xlt]

The labor cost was extremely reasonable. The shop probably made some money on the parts to offset the labor. Your engine should last another 150K miles!

That's the hope. I am back at the shop now. They asked me to drive around and look for any issues.

They didn't line my hood up properly after removing it, they also added some nice scratched from leaning over on the hood while working on it. I will likely let that slide as my tru I isn't a show queen, I just want it trustworthy a nd reliable.

I found a leak at the trans cooler/ warmer line connections and my radiator decided to releve itself of some coolant through the drain on the bottom.

They are cleaning it off after those leaks were addressed and we are going to check it again.

 

[darkranger]

Sealing washer

Anyone who has a leaking chain tensioner needs to consider the following fix if you have exhausted all other options other than pulling and replacing the head.

See link below.
http://www.mcmaster.com/#94154a815/=wryg5i

We tried everything.
New crush washer, no crush washer, second $10 crush washer, Brass washer that comes with the SOHC timing chain tool kit, Gasket maker Black, Gasket maker Red (from the dealer), JB Weld, more JB Weld, buffed mating surface with die grinder and buffing pad, new tensioner, double crush washer.

$3.60 sealing washer from McMaster Carr and thread lock-tight, DONE! ZERO LEAKS!

Yes the washer is thicker than the crush washer but the tensioner seems to be working great. No chain rattle at all.

Good luck.

 

[Sparkwright]

Anyone who has a leaking chain tensioner needs to consider the following fix if you have exhausted all other options other than pulling and replacing the head.

See link below.
http://www.mcmaster.com/#94154a815/=wryg5i

We tried everything.
New crush washer, no crush washer, second $10 crush washer, Brass washer that comes with the SOHC timing chain tool kit, Gasket maker Black, Gasket maker Red (from the dealer), JB Weld, more JB Weld, buffed mating surface with die grinder and buffing pad, new tensioner, double crush washer.

$3.60 sealing washer from McMaster Carr and thread lock-tight, DONE! ZERO LEAKS!

Yes the washer is thicker than the crush washer but the tensioner seems to be working great. No chain rattle at all.

Good luck.

I am having same gushing of oil past the new tensioner on a new cylinder head, despite trying washer, no washer, and washer with black gasket sealant.

Darkranger: are you still having success with the McMaster Carr sealing washer? Any troubles with the tensioner not working or developing noise (wear) on the timing chain and components?

- Sparkwright

 

[2000StreetRod]

grease?

The inner diameter of the compression ring is significantly larger than the outer diameter of the tensioner near the sealing face. Did you use some thick grease to keep the compression ring centered? If it drops out of position there will be a large leak.

It is very easy to cross thread the tensioner because of the pressure from its spring. The tensioner should be installed by hand compressing the spring while turning the head. As I recall it is possible to turn the tensioner by hand at least two or three rotations. If a wrench or socket with drive is required after only one rotation the tensioner is probably going in cross threaded.

 

[Sparkwright]

Didn't try grease. The third try was with black RTV sealant on both sides of the metal washer, using the RTV to keep the washer from slipping (similar to what grease would have done). Also, the washer OD is slightly larger than the width of the flats on the tensioner head, so I checked by feel that the washer was still centered before final tightening.

I used the trick of cranking the engine a quarter - 1/3 turn (clockwise) by hand to get some looseness in the timing chain so that the tensioner would thread in easily by hand until many threads were engaged. I made sure of no cross-threading.

The "new" cylinder head has some surface divits near but not quite at the tensioner sealing surface; maybe from some prior corrosion that was cleaned off during the re-manufacturing process. These surface holes are a bit deeper than what sanding or buffing would be able to take out; thus my turning to the RTV.

I do wonder if the washer is correct. It is the washer supplied with the Cloyes timing chain kit. There were no washers on either of the tensioners I removed off the engine. The washer ID is just a bit larger than the tensioner OD where it sits, which matches others' descriptions; but it is totally flat where some of the descriptions say that Ford version is slightly conical.

My thoughts are to go get the Ford version of the crush washer (conical?); and install with thread-locker on the sealing surfaces, and let set for at least a day before running and getting oil onto the seal. And, if that doesn't work, try the sealing washer method suggested by Darkranger, though I really wonder if the tensioner would work sufficiently because not being threaded in as far against the timing chain guides, and if the oil hole into the tensioner would not get plugged when the sealant squishes out of the sealing washer.

Any ideas or suggestions?

 

[2000StreetRod]

compression ring

Below is a photo of the Borg Warner tensioners I purchased years ago.

The compression rings look similar to the one that came in the Ford 00M12 kit.

You're correct that installing a compression ring or washer would decrease the piston pressure against the guide because the tensioner spring would be less compressed. However, the spring pressure only matters when the oil pressure is low as during engine start. I don't remember if the OEM ring was cupped but that would help compensate for any marred surface in the head face.

 

[Sparkwright]

When I pulled the tensioner back out, found that the crush washer actually had been misaligned, and now is in an oblong egg shape. I have ordered a replacement crush washer.

 

[Sparkwright]

Update: installed the replacement crush washer with carefully placed blue LockTite, and it finally held oil. Now, about 3.5 months and 900 miles later, as I investigate a sudden misfiring/timing issue on the whole right bank (may or may not be related to prior problems installing the right tensioner), I noticed that the right tensioner head is seaping oil. Looks like I get to try again.

 

[Sparkwright]

Another update: Compression tests and leak-down testing pointed to a problem with right timing chain: none of the intake or exhaust valves on right bank were opening when I rotated engine. Pulled intake manifold and found a cup of gasoline sitting on top of each of the intake valves. Pulled the right valve cover to find right timing chain missing.
So... pulled the engine... again. (Experience helps: done in 2 days by myself vs. over 3 weeks last fall.)
==> Right timing chain is broken and guide is shattered. (Only 900 miles)

I suspect that the replacement right tensioner as a major culprit since I had so much prior trouble getting it to seal. Also suspect I might have gotten the timing slightly off on the right bank trying to crank the shaft to get to a low chain tension position to get the tensioner to start threading by hand (but the engine did run OK without codes..). Or, it might have been something else such as part failure of the off-brand (Cloyes) parts; I will investigate further.

 

[Sparkwright]

Another update, and request for ideas on how to permanently seal the right rear tensioner

Still having continuing trouble getting the right rear timing chain tensioner to seal. It drips at about one drip per two minutes.
History: rebuilt engine because of failed timing chain guides at 180,000 miles, and tried starting it up in January 2016.
Try #1: The replacement timing chain set's crush washer, and just torqued to spec.: Gushing oil. About a quart on the driveway in minutes.
Try #2: Re-seated, Extra-torque: more oil on driveway.
Try #3: Re-seated with black gasket sealer & torqued: Oil on driveway. Found the crush washer had been offset and was now oblong.
Try#4: New Ford crush washer (has a slight cone); Permatex blue thread locker to keep positioned; Torqued; let set for 2 days for thread locker to set up. ==> Finally, no noticeable leak (at least for a while). Later found was seeping oil.

May 2016: 800 miles down the road one of the replacement timing chains snaps in two. Happens to be the right rear camshaft timing chain. Same spot as the troublesome tensioner. Install a Ford timing chain cassette this time around, complete with a Ford tensioner.
Try #5: Another new Ford crush washer. Permatex blue thread locker. Assured washer centered. Torqued to spec. Setup was a few days before starting the engine: Initial startup had a noticeable oil seep.
Try #6: Another New Ford crush washer; Permatex blue thread locker to keep positioned; Torqued a bit more than spec; let set for 2 days for thread locker to set up. ==> No noticeable seep. (at that time)
June 2016 - May 2017: have a oil seep somewhere in back of engine that smokes; noticeable when stopped at stoplights. Later find oil seeps at all timing chain fastener ports on the heads, including major seep at the left rear tensioner.

May 2017; 9000 miles after first rebuild: Oil pressure drops out; find that there are plastic shavings clogging oil suction; from (you guessed it) torn up timing chain guides. Pull engine again (3rd time), and find left front chain has eaten through the replacement kit guides, and that chain has 8 cracked links. Pull all of the remaining "replacement" timing chain kit and replace with Ford parts.
Try #7: Another new Ford Crush washer; Permatex white thread sealant; ensure centering of the washer; torque to spec; let sit for about a week before startup of engine. ==> No initial oil seeps!

But..., still have an oil seep somewhere that smokes under the hood.
talcum=powdered the engine; found that it is a slow drip (once per two minutes) from the same left rear tensioner bolt, directly down onto the exhaust manifold.

So, any ideas?

 

[2000StreetRod]

I admire your persistence! I suspect that the face of the head that mates with the tensioner has a gouge that allows leakage. The standard compression washer may not be thick enough or soft enough to conform to the rough surface and achieve a good seal. I've had good luck with Permatex high temperature red RTV silicone gasket maker.

 

[Sparkwright]

Followup on sealing the right rear tensioner (finally found a solution!):

I thought about the red RTV silicone, and, per my engineering experience with lube oil systems on much larger equipment, decided against RTV. When RTV breaks down, it comes off in chunks which can clog small valves, such as the check valve in the tensioner. Many large machinery OEMs will not warranty components in a lube oil system in which they find any trace of RTV.

Try#8: So, I tried Type 1 Gasket Sealant. Billed as quick-setting (4 hr to set, 24 hrs to harden), I cleaned the tensioner and aluminum head surfaces of all oil. Also emptied the tensioner of oil so it would not squeeze out during insertion. Started the engine up 5 hours after installation: immediate Drip-Drip-Drip onto the exhaust manifold. Uninstalled and found the oil had washed out the sealant.

Try#9: Try#2 with the Type 1 Gasket Sealant. But let it set up for 72 hours before starting the engine. This time a slow Drip - Drip. Days later when I came up with a different method (Try#10, below), I uninstalled and found that the Type 1 Gasket Sealant had not adhered to nearly anything. Barely to the tensioner. Not at all to the crush washer, barely to the aluminum head past the tensioner outer edges. The oil seamed to have washed it all out. (Side note: on this uninstall, found that the tensioner check valve was no longer holding oil. Had to clean, fill, pump-out, repeat several times to get it working correctly. DO NOT INSTALL TENSIONER IF CHECK VALVE DOESN'T HOLD OIL ==> Will ensure tensioner failure and then timing chain guides/chain/engine.

So Try #10 (which finally worked!): 2-Part Epoxy (J-B Weld). I decided I had to use something that would adhere despite the very narrow band of contact between the tensioner. I had put off this approach because I know at some point in the future (75k miles), I will have to uninstall this tensioner. Considering that this is a 27mm bolt head, I think that I will have the leverage needed to break this bond if I have to. Epoxy needs a rougher surface to adhere, so I roughed up the aluminum head mating surface with 40 grit sandpaper (in circular pattern, no radial scratching). Also "roughed" up the tensioner bolt mating surface (also in circular pattern), and removed the glossiness off the surface of the crush washer. This time I did partially (1/3) fill the tensioner with oil to confirm that the check valve was working. Equal parts of epoxy and hardener, spread completely but thinly on all mating surfaces (tensioner under bolt head, both sides of crush washer, and on aluminum head outside). Inserted tensioner by hand threading most of way in, and tightened to 45 ft-lbs. Let set for 3 days before starting engine. It worked! No drips at all! I have since driven 200+ miles with still no drips. No longer have to smell burning oil when sitting at stop lights.