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Ask Ron Your Own Question
Ron, ASE Certified Technician
Category: Ford
Satisfied Customers: 34136
Experience:  23 years with Ford specializing in drivability and electrical and AC. Ford certs and ASE Certs
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Just reading around to try and find the source of the oil

Customer Question

just reading around to try and find the source of the oil leak on the back of a 98 4.0 OHV motor. Doesn't appear to be valve covers and I think it is too high for a rear main
JA: Have you ever replaced the gaskets? Maybe the hoses?
Customer: they were done by someone else last year
JA: Are you fixing your 98 yourself? What have you tried so far?
Customer: i was just looking last nite and there appeared to be a type of sensor on the rear passenger side of the motor behind the intake where i am seeing some pooled oil
JA: Anything else you want the mechanic to know before I connect you?
Customer: no, just trying to see what that sensor is or leak points for oil at the top rear of the motor not including valve cover gaskets
Submitted: 3 months ago.
Category: Ford
Expert:  Ron replied 3 months ago.

Hello. My name is ***** ***** I am happy to assist you today. Give me just a moment to review your post, and I'll be right back with the help you need.

Customer: replied 3 months ago.
Expert:  Ron replied 3 months ago.

The most common cause for the type of oil leak your describing if you sure its not coming from the remain seal is usually caused by a leaking intake gasket. Are you able to get a mirror back there to make sure its coming from above the bell housing?

Customer: replied 3 months ago.
i wasn't sure if the rear lower intake gasket at the rear would leak oil, i am assuming the guy who put the heads on used the cork gaskets. Just got the truck a month ago and working through the issues. It was a mobile mechanic that put the heads on so not sure about the quality that was done, was before I owned the truck
Customer: replied 3 months ago.
didn't wanna tear down the top half of the motor if that spot wouldn't leak oil. Wasn't sure if the rear was a coolant area or oil area. Oil looks good so not getting any mixture and I have no vacuum leaks or codes
Expert:  Ron replied 3 months ago.

I would try getting back there with a mirror and having a look to verify its the intake before you rip it down. If its leaking it usually at the corners where the intake meet the heads. If you need the removal steps I can post those as well. Let me know.

Customer: replied 3 months ago.
there is some type of sending unit on the rear passenger side that has a hold down clamp that i see oil pooled, any idea what that unit is. would like to start there since it is wetter there than anywhere. I used a mirror last nite while on the rack, that is how i saw the wet sensor or sending unit. Appears to go straight down in the block on the pass side with a hold down bolt
Expert:  Ron replied 3 months ago.

The should be the cam shaft sensor and synchronizer. It dose have an O ring on it as well. See the link below.

Customer: replied 3 months ago.
I haven't pulled it. So if truck is running fine, pull that sensor and replace the o-ring on it. I have a large o-ring kit, would it work, or is it something i should just replace the whole sensor. Also is that part a drop in or does it have to be indexed a certain way. thanks
Customer: replied 3 months ago.
I see the indexing instructions now, sorry for asking that again.
Expert:  Ron replied 3 months ago.

The O ring is actually on the synchronizer which the sensor mounts to and if your removing the synchronizer you will need the alignment tool shown in the steps .

Customer: replied 3 months ago.
do i replace the synchronizer or just pull it out and change the o-ring on it. Also does the dealership sell that tool, or do I need to get it online
Expert:  Ron replied 3 months ago.

You can just remove it and replace the O ring . You can get the tool at most tool supply store and also most auto part stores. Its a common tool.

Customer: replied 3 months ago.
I will give that a try this afternoon, it mentions removing the upper intake manifold, if i took the passenger fenderwell out, i wonder if I could get it without removing the UIM
Customer: replied 3 months ago.
BTW i was charged 28 bucks earlier, was that for a one time charge, or the monthly membership, it asked me for a login and such so I am not sure what I bought?
Expert:  Ron replied 3 months ago.

I have always just removed the intake to get the clearance you need. It has to come up pretty high to get it complete out. You can try coming through the inner fender and see it may work. If not then plan on removing the upper intake. You are not signed up for a monthly charge so once you rate my service you will only be charged one time.