timing chain tensioners | Ford Explorer Forums - Serious Explorations

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timing chain tensioners


February 20, 2015
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City, State
valparaiso, in
Year, Model & Trim Level
2004 ford explorer
Hi got a question on my right side head timing chain tensioner. I changed it and went to start the vehicle and now i got a massive oil leak. I torqued the tensioner down to 50 ft lbs and it still pouring out oil. Was wondering if there anything i can do to get the leak to stop. Get a seal like the left head tensioner had or use thread sealant? Any info will be grateful thanks

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Where can i get one at?? No local parts store has one that big. And when i installed it i think i cross threaded it cause it was hard to go in

Tensioner metal O ring XU2Z6M252AA - Available from Ford dealer.
Use grease to keep O ring in position while threading in tensioner.

They say not to use a o ring on the right head tensioner cause it will block the oil hole on the tensioner

blocking the oil port

They say not to use a o ring on the right head tensioner cause it will block the oil hole on the tensioner

That may be true if you don't use the O ring available from the dealer.

The red arrow identifies the oil port. The green arrow identifies the sealing surface. The blue arrow identifies the taper between the port and sealing surface. If the inner diameter of the compression ring is less than the outer diameter of the taper at the sealing surface it can block the port. If the compression ring is too thick but the correct inner diameter it can shroud the port. The compression ring from the dealer is the correct diameter and thickness. My workshop manual has the specified torque values for the tensioner with and without the compression ring with no caution of the ring blocking the port. If the ring slips out of position when screwing in the tensioner it can block the port. But it will also not seal and cause a massive oil leak.

Ok thanks guess ill go order one from my local ford dealer. Also if i cross threaded the threads will that cause a oil leak? And if so what size tap would i need to repair the threads. Cause when i put the new tensioner in i thought you could screw it in by hand. Mine i couldnt. Had to use a breaker bar to tighten.

cross threading

It is easy to cross thread the tensioner because the piston spring must be compressed while starting the threads. However, because the threads are so fine (mechanical advantage) you should be able to turn it several turns by hand while pressing against the tensioner. After that many turns it should not cross thread when screwed in the rest of the way with a ratchet. You may have problems finding a tap to chase the threads. I don't know the size or pitch but the size is large and the pitch unusually fine for the size. I couldn't find a bolt with the same size and pitch. If you find a tap that fits I suspect it will be expensive.

Yeah i am finding that out now lol. I am hoping a tool and die place will have one. But yeah i can get it to turn in by hand a little just enough to bit and then i used a rachet but its extremely hard to get it in. And i can get the right torque on the bolt cause with it being so hard when i set it to the right torque spec it is already at the spec i set it at before its even seeded to the head

cross threaded

It sounds to me like it is cross threaded and not seated. The result is a large oil leak. That is very easy to do if not taking extreme care when starting the thread process. As I recall, after starting mine by hand I screwed them the rest of the way with a standard ratchet drive. I only needed the torque wrench when the tensioner face was seated against the head. Remember, the tensioner spring is so weak that the piston can be compressed into the cylinder using just your thumb.

Unfortunately, I don't have any good advice to solve a cross thread problem that was torqued as much as you describe. The head is soft and the tensioner housing is hard. You might remove the tensioner and check it for damage. If it is damaged the head will be more damaged. You may need a die for the tensioner as well as a tap for the head. Find a good machine shop and get advice from an experienced machinist. You may have to use some type of bonding sealant or even replace the head.

Well when i removed it. The threads on the tensioner really didnt look bad. I just think i need to find a tap to basically chase the threads and clean them out in the housing. And hopefully that fixes it. I even went out and bought a new tensioner to be safe for after i chase the threads. And what is the torque specs for that tensioner without the metal o ring. I dont think i need one cause the old one didnt have it and it didnt leak

tensioner torque

If using a new washer/compression ring torque the tensioner to 32 ft-lbs. If reusing the old washer/compression ring or none torque the tensioner to 49 ft-lbs.

Be advised that some members had to increase the above in order to stop leaks. If the head sealing surface is scratched or not smooth the compression ring will help prevent leakage.

Well i found out what size tap i need. Its a 22mm with a 1.5 pitch