Quick question relating to 4.0 sohc timing drive, specifically about the tensioners. Need somebody that has decent experience with 4.0 sohc timing dri

[Devan]

I jus got done replacing blown head gaskets nd replacing a busted chain guide on the rear for the passenger side cylinder head. I got everything tightened bak up and have no problem turning the motor over by hand however as i do so the chain guides that lay directly on the tensioners push the tensioners in and then when i turn the motor over a lil more they pop out. Both sides do this. Is this normal? I kno their prolly compressing all the way cuz their is no oil pressure or oil in the tensioners but i jus wanted to make sure this is normal for the tensioners to compress all the way and then pop out when you turn the motor over by hand counter clockwise. If nec i can take a vid and post a youtube link so u can see what im talking about. Been building performance builds for over a decade nd worked as a ford tech for 3 yrs till i outgrew my dealership but i am extremely delicate when it comes to timing drives, especially with one like this german designed 4.0 sohc. Im almost positive what im seeing is normal but i just wanted to check with somebody that has a decent amount of experience with the timing drive on the 4.0 sohc. Also if i bled the air out of the tensioners by compressing the tensioner and then submerging it in oil and then letting the tensioner uncompress so that it sucks oil into the tensioner, would they still fully compress and pop out when i turn the motor over by hand or would it just push the oil out or would the tensioner not compress as much when turning the motor over by hand? That ill find out soon enuff tho lol. But any help asap wuld be greatly appreciated. Been working on my BoostedXPLR Sport for over a week straight from wake till sleep and i shuld be rdy to fire it up today so a lil quick help would be extremely appreciated. Thx in advance.

 

[koda2000]

I though I had a blown head gasket on my 4.0L SOHC. It turned out that both my heads had cracks between the valve seats. I didn't think cracked heads would be an issue on aluminum heads, but apparently the PO of my truck had severely overheated the engine at some point. Did you carefully inspect your heads, or have someone look a them? When I took mine in to a place that remans heads to have them resurfaced, the guy immediately showed me 3 separate cracks.

As for as the hydraulic chain tensioners, I replaced all my timing chain components due to multiple problems, including the hydraulic tensioners, with Ford OE parts. When the engine was put back together I did spin it clockwise 4 times to check for any binding or noises and to verify my cam/crank timing, but I honestly didn't pay any attention as to whether the dry tensioner pistons moved or not. I suspect it might be normal for the tensioner pistons to move in and out, but I can't say for sure. All I know is that once I built oil pressure and allowed the engine to start it was fine. It now has over 1000 miles on it, but I plan to install a pre-oiler soon as I am of the belief that lack of oil pressure to the tensioners on cold start is likely what breaks the cassettes. Until I get around to installing a pre-oiler I crank my engine using the starter motor/accelerator pedal held to the floor before allowing it to cold-start before I see oil pressure.

Some members here have experimented with using Polaris manual chain tensioners in place of the hydraulic ones and have managed to eliminate their timing chain rattle, but these will only work if there hasn't been previous damage to the cassettes/guides.

 

[Devan]

I though I had a blown head gasket on my 4.0L SOHC. It turned out that both my heads had cracks between the valve seats. I didn't think cracked heads would be an issue on aluminum heads, but apparently the PO of my truck had severely overheated the engine at some point. Did you carefully inspect your heads, or have someone look a them? When I took mine in to a place that remans heads to have them resurfaced, the guy immediately showed me 3 separate cracks.

As for as the hydraulic chain tensioners, I replaced all my timing chain components due to multiple problems, including the hydraulic tensioners, with Ford OE parts. When the engine was put back together I did spin it clockwise 4 times to check for any binding or noises and to verify my cam/crank timing, but I honestly didn't pay any attention as to whether the dry tensioner pistons moved or not. I suspect it might be normal for the tensioner pistons to move in and out, but I can't say for sure. All I know is that once I built oil pressure and allowed the engine to start it was fine. It now has over 1000 miles on it, but I plan to install a pre-oiler soon as I am of the belief that lack of oil pressure to the tensioners on cold start is likely what breaks the cassettes. Until I get around to installing a pre-oiler I crank my engine using the starter motor/accelerator pedal held to the floor before allowing it to cold-start before I see oil pressure.

Some members here have experimented with using Polaris manual chain tensioners in place of the hydraulic ones and have managed to eliminate their timing chain rattle, but these will only work if there hasn't been previous damage to the cassettes/guides.

The pre oiler is certainly a good idea, i inspected my heads throughly, no cracks and cleaned the **** out of the entire motor from the pistons up. This is a 2nd motor i had laying around that i was gonna build with like 120k on it. the original motor in my truck cracked cylinder 4 at 320k nd the break was identical to what ive seen before with boosted 4.0s, block is fine tho. So im gonna rebuild the original motor and original trans too. i didnt even really get a chance to tear the 2nd motor down at all before having to jus thro it in. If i did i prolly wouldn't have tried to replace the exhaust manifold gasket 5 or 6 times on the driver side trying to track down an exhaust leak, i would have known the head gasket was blown on cyl 5 since day one which was the exhaust leak i was hearing. plus the valley use to fill up a little with fluids. When i went to tow a trailer recently the head gasket leak blew out worse and became unmanageable. And i would hear a pretty significant rattle under high boost at high rpm and load when i wuld be really getting on it nd if i took the time to look into the motor i wuldve seen the broken chain guide on the backside. But now the motor is as fresh as can be. The bottom of the heads and the valves and the top of the block nd pistons all cleaned. I jus wish somebody could confirm what im seeing with the tensioners b4 i fire this thing.

 

[koda2000]

Did you install new Ford hydraulic tensioners? People have reported problems with aftermarket tensioners and you don't want to reuse your old tensioners or washers, though the washer's can be reused but it changes the torque spec on the tensioner. It should not be necessary to soak/pre-fill your tensionsers with oil, however before allowing the engine to start for the first time you should build oil pressure by cranking.

As far as the movement your seeing in your dry tensioners when you spin the engine over by hand, you're causing the chain tension to increase against the guide and tensioner, perhaps that's why you're seeing the piston get pushed in and there's no oil in the tensioner to resist this, only the internal spring. I can't say for sure, but that makes sense to me. Maybe someone else can give the assurance you're looking for, but I've never seen this question asked before (in the forum nor in the many video's I've watched).

The slack in the chains before oil pressure builds is why pre-oiling is so important with this engine.

 

[donalds]

@koda2000 wise one are you

 

[Devan]

Did you install new Ford hydraulic tensioners? People have reported problems with aftermarket tensioners and you don't want to reuse your old tensioners or washers, though the washer's can be reused but it changes the torque spec on the tensioner. It should not be necessary to soak/pre-fill your tensionsers with oil, however before allowing the engine to start for the first time you should build oil pressure by cranking.

As far as the movement your seeing in your dry tensioners when you spin the engine over by hand, you're causing the chain tension to increase against the guide and tensioner, perhaps that's why you're seeing the piston get pushed in and there's no oil in the tensioner to resist this, only the internal spring. I can't say for sure, but that makes sense to me. Maybe someone else can give the assurance you're looking for, but I've never seen this question asked before (in the forum nor in the many video's I've watched).

The slack in the chains before oil pressure builds is why pre-oiling is so important with this engine.

When it comes to the timing drive for the 4.0 SOHC their is no substitute for official Ford parts. I really wish their was. I have done extensive research on this. Actually I think there is one 4.0 sohc timing drive performance upgrade and that is for the chain that goes from the crank to the jackshaft, I think Tom Morona Motorsports puts out a double chain with double sprockets for crank to jackshaft. Tom Morana Racing Engines
Although I don't know if it would fit the timing chain guides or if there's replacement timing chain guides in the kit. Also it doesn't list if it's for the OHV or the SOHC however I know the blocks are extremely similar.
The quality of anything aftermarket is pretty much inferior to the quality of Ford timing drive components. I've actually seen websites that compare quite a few aftermarket kits to Ford kits and the pictures illustrate pretty good just how bad aftermarket kits are. Plus if you go on Amazon and you look at reviews for aftermarket kits from somebody that has put decent mileage on their aftermarket kit they'll say something like oh it only lasted a month or it destroyed my motor or something along those lines. So therefore yes my hydraulic tensioners are fresh. And yes I plan on building oil pressure before firing. One thing that is weird tho is the original washer on the tensioner is rlly thin and the copper washers that came with new ford tensioners were alot thicker.

But yes i think what i am seeing is normal as well. Tension builds on the chain as i turn the motor over counter clockwise pushing the guide and pushing the tensioner in then turn a lil further and it pops out. Both sides do this. When turning clockwise it doesnt happen as rough. I am going to pre-fill the tensioners and see what happens. I'm almost positive I'm just being paranoid because I just spent mad time on this thing and that they're normal. Will update

 

[koda2000]

When it comes to the timing drive for the 4.0 SOHC their is no substitute for official Ford parts. I really wish their was. I have done extensive research on this. Actually I think there is one 4.0 sohc timing drive performance upgrade and that is for the chain that goes from the crank to the jackshaft, I think Tom Morona Motorsports puts out a double chain with double sprockets for crank to jackshaft. Tom Morana Racing Engines
Although I don't know if it would fit the timing chain guides or if there's replacement timing chain guides in the kit. Also it doesn't list if it's for the OHV or the SOHC however I know the blocks are extremely similar.
The quality of anything aftermarket is pretty much inferior to the quality of Ford timing drive components. I've actually seen websites that compare quite a few aftermarket kits to Ford kits and the pictures illustrate pretty good just how bad aftermarket kits are. Plus if you go on Amazon and you look at reviews for aftermarket kits from somebody that has put decent mileage on their aftermarket kit they'll say something like oh it only lasted a month or it destroyed my motor or something along those lines. So therefore yes my hydraulic tensioners are fresh. And yes I plan on building oil pressure before firing. One thing that is weird tho is the original washer on the tensioner is rlly thin and the copper washers that came with new ford tensioners were alot thicker.

But yes i think what i am seeing is normal as well. Tension builds on the chain as i turn the motor over counter clockwise pushing the guide and pushing the tensioner in then turn a lil further and it pops out. Both sides do this. When turning clockwise it doesnt happen as rough. I am going to pre-fill the tensioners and see what happens. I'm almost positive I'm just being paranoid because I just spent mad time on this thing and that they're normal. Will update

Odd, I've never seen genuine Ford timing chain tensioners come with any washers, let alone thick copper washers. I've always had to purchase the thin washers separately. The only thick copper washer I've seen came with my OTC cam timing tool kit. For the record, I've never had a thin tensioner washer leak.

 

[drdoom]

Never turn an engine in the opposite direction. No wonder you are having trouble.
These type of timing chains have a traction side and a slack side. The tensioners purpose is to take up the slack, and was never intended to hold traction. If you rotate in the opposite direction you can do a lot of damage. I am no expert but every overhead cam engine I have ever worked on is similar in this regard.

 

[koda2000]

Never turn an engine in the opposite direction. No wonder you are having trouble.
These type of timing chains have a traction side and a slack side. The tensioners purpose is to take up the slack, and was never intended to hold traction. If you rotate in the opposite direction you can do a lot of damage. I am no expert but every overhead cam engine I have ever worked on is similar in this regard.

@Devan - I missed where you said... "i jus wanted to make sure this is normal for the tensioners to compress all the way and then pop out when you turn the motor over by hand counter clockwise." Never do this. No wonder the tensioners are doing what you're seeing.

 

[Devan]

@Devan - I missed where you said... "i jus wanted to make sure this is normal for the tensioners to compress all the way and then pop out when you turn the motor over by hand counter clockwise." Never do this. No wonder the tensioners are doing what you're seeing.

Never turn an engine in the opposite direction. No wonder you are having trouble.
These type of timing chains have a traction side and a slack side. The tensioners purpose is to take up the slack, and was never intended to hold traction. If you rotate in the opposite direction you can do a lot of damage. I am no expert but every overhead cam engine I have ever worked on is similar in this regard.

Actually in order to lock the crank at TDC with the crank tool it is necessary to spin the engine counter clockwise at least a little. And im also pretty sure the Ford PTS workshop manual and Alldata which is still ford documentation said to rotate the engine counter clockwise although i did a quick search jus now and didnt see that but i only looked at one section but I could have swore it said rotate counter-clockwise somewhere. And it's not like I had the tensioners all the way in when turning the motor over, like I said before though when turning clockwise they seem fine which is the normal direction of the engine while in operation, I was just making sure I wasn't seeing a problem cuz i jus spent a week and a half straight from wake till sleep workin on this thing and this truck is a lil more complicated then your average 4.0 sohc so it takes more time. Dual alt, dual batt, thunderbird eaton m90 + intercooler and meth inj, and so much more and i also had a busted chain guide on the back for the passenger side cyl head and to get to the lower bolt that holds the chain guide in, trans has to come out which means exhaust, dshafts, tcase, trans cross member, wiring and more has to come out jus for that one lil bolt right on the inside of the bellhousings perimeter where it meets the engine.
This is the 2nd motor in the truck which actually came out of an 08 mustang v6 with like 120k on it, i was planning on rebuilding this motor with perf internals and mad work but my original motor cracked a piece of cyl 4 at 320k so i had to drop that 2nd motor in without really even gettin a chance to tear it down to take a look at it, woulda saved me alot of time. But now the bottom of the cyl heads and valves are completely clean and so is the top of the engine block and the pistons and fresh head gaskets installed along with the rear chain guide. If the original motors mileage is any indication of how long this next motor will last I'm fine with it. Because i got 320k out of the original motor without touching the timing drive except for replacing the tensioners, and if i wasnt racing some other truck i wouldnt have cracked a cylinder and even as it was there was no damage done to the block, I could have just replace the spark plug and probably kept driving at least for a little with the cracked cylinder. i jus finished all up underneath the truck now im dealin with the motor. Shuld be rdy to fire today but i been sayin that for a day or 2 now lmfao

 

[donalds]

Actually in order to lock the crank at TDC with the crank tool it is necessary to spin the engine counter clockwise at least a little. And im also pretty sure the Ford PTS workshop manual and Alldata which is still ford documentation said to rotate the engine counter clockwise although i did a quick search jus now and didnt see that but i only looked at one section but I could have swore it said rotate counter-clockwise somewhere. And it's not like I had the tensioners all the way in when turning the motor over, like I said before though when turning clockwise they seem fine which is the normal direction of the engine while in operation, I was just making sure I wasn't seeing a problem cuz i jus spent a week and a half straight from wake till sleep workin on this thing and this truck is a lil more complicated then your average 4.0 sohc so it takes more time. Dual alt, dual batt, thunderbird eaton m90 + intercooler and meth inj, and so much more and i also had a busted chain guide on the back for the passenger side cyl head and to get to the lower bolt that holds the chain guide in, trans has to come out which means exhaust, dshafts, tcase, trans cross member, wiring and more has to come out jus for that one lil bolt right on the inside of the bellhousings perimeter where it meets the engine.
This is the 2nd motor in the truck which actually came out of an 08 mustang v6 with like 120k on it, i was planning on rebuilding this motor with perf internals and mad work but my original motor cracked a piece of cyl 4 at 320k so i had to drop that 2nd motor in without really even gettin a chance to tear it down to take a look at it, woulda saved me alot of time. But now the bottom of the cyl heads and valves are completely clean and so is the top of the engine block and the pistons and fresh head gaskets installed along with the rear chain guide. If the original motors mileage is any indication of how long this next motor will last I'm fine with it. Because i got 320k out of the original motor without touching the timing drive except for replacing the tensioners, and if i wasnt racing some other truck i wouldnt have cracked a cylinder and even as it was there was no damage done to the block, I could have just replace the spark plug and probably kept driving at least for a little with the cracked cylinder. i jus finished all up underneath the truck now im dealin with the motor. Shuld be rdy to fire today but i been sayin that for a day or 2 now lmfao

Love to see some engine bay pictures of your supercharged ride

 

[allmyEXes]

This is a question and remember that I do not have any experience with pre-oilers. Could the pre-oiler system be powered up straight to the battery to pressurize the oiling system thus pumping up the tensioners?

 

[donalds]

This is a question and remember that I do not have any experience with pre-oilers. Could the pre-oiler system be powered up straight to the battery to pressurize the oiling system thus pumping up the tensioners?

Yes just use a button on the dash
Hold it down till gauge shows pressure then let go and start
Done

The controller does this for you

 

[allmyEXes]

...Just to pressurize while the engine is being worked on like installing the camshaft alignment tools...

 

[donalds]

...Just to pressurize while the engine is being worked on like installing the camshaft alignment tools...

Sure but the pressure only last so long a few sec...