Dreaded Timing chain tensioner

[gto78]

I am in the dead center of HELL :fire: right now. I started off with a really loud clatter in the timing cover. Took it off and found the tensioner broken in pieces. I replaced it and the chain- but when i loosened the bolt for the jackshaft sprocket, the cams BOTH moved. NOW i have to find the cam positioner tool and line everything up and start over.

So far i removed both oil pans, replaced the pan gaskets, replaced the lower front chain and tensioner, and reinstalled the oil pans. NOW i have to rip apart the top of the engine and access the cams so i can realign the cam and then resecure the bolt for the jackshaft sprocket. WHAT A NIGHTMARE. THANKYOU FORD FOR YOUR DUMBASS DESIGN. I am impressed with this engine at the same time as I want to smash it with a sledge hammer. It performs great, but was designed by a total P O S moron who obviously doesnt work on engines. I cant believe how many hours I'm wasting doing the absolute simplest job- changing a timing chain.

WTF FORD?

 

[Explorerhucker]

Amen brotha!

I contemplated doing this job as well but man it looks nasty. Especially the rear tensioner. Indeed a bad "design". Feel free to join my post below this one.
Take some pics!

 

[gto78]

i've taken a few pics, i dont know how helpful they are yet. I will by the time i'm done.
Right now I'm having a major problem of finding the special "FORD" tool to "align" the cams. What a total crock of ****. Why couldnt they just leave well enough alone and do something simple like put a dot on one part of the cam, and when that dot is pointing a certain direction that means everything is kosher and aligned. Great Idea right, gee, I think they did something like that on every engine for the last 80 years.

Well I have everything torn apart, and it could be running right now but...... I have to save my pennies and buy a $550 tool set just to make sure the cam is pointing the right way first..... Can you tell i'm pissed?

If anyone here knows where I can get the positioning tool on a loaner program please let me know. I will gladly pay someone to use the tool and return it in perfect condition.

A little about me: I've been an aircraft mechanic for over 10 years and on a daily basis I tune and replace aircraft piston engines. I have to know a little bit about everything, and a LOT about even more things. In addition I have to learn just a little bit more about each particular make and model airplane as I work on it, and after ten years I still learn something new everyday. With that said, I have NEVER ever seen such a cluster **ck as this 4.0 sohc engine. I've built many car race engines, with no problems at all, AT ALL, but this is insane.

 

[je5]

German engineering. Fart fer nugen.

 

[Majisto]

And you can blame France for the transmission. But honestly, I have over 180K on my stock SOHC and it has been performing wonderfully. I don't think Ford really thinks that the timing chain needs to be replaced ever. I've never had to do a timing chain job on any Ford I've owned. They are extremely reliable. I prefer the chains anyway. Nothing like a timing belt car that's interference. Thanks Honda. :thumbdwn:

 

[ricjin]

Timing chain is an interference motor in the 98 sohc, ask my engine, chain snapped after tensioner let go(120,000 miles). bent all the open valves badly, plastic chards all in my motor to, had an engine guy drop a 2002 sohc motor with 50,000 miles on it. Runs like a charm now.

 

[gto78]

UPDATE:
I am almost completely finished with the job- finally. I found someone locally with the cam alignment tools. I was having a hard time getting the crankshaft to stop exactly at TDC for some reason, so I figured what the hell, why not let it be advanced 1 or 2 degrees. WELL that didnt workout so good because unfortunately my crank sensor was not mounted in the right direction at the time that I was relying on it to tell me where number one TDC was located. Once I repositioned it corretly, I found out that my cam timing is now actually retarded about 5 degrees....

Unbelievable. I finished the job, started it up, and it runs better than it ever has since we bought it in 1998. It idles like a frikin caddy. No noises, revs extremely smooth. It's a shame that I have to take the intake and valve covers off all over again just to reposition the cams. I wish I would have noticed the crank sensor BEFORE I put the intake back together. With the cam timing retarded that means less vacuum, less torque, and less mileage. No good.

 

[gto78]

On the idea of cam timing.... has anyone else experimented with advancing it on their 4.0 sohc engine? I have it advanced on my potiac 400, because of the giant cam profile. I advanced it to better match my gear ratio and make it more streetable, and to lower the rpm power curve. But the cam is already so smooth on the 4.0, and the compression ratio is 9.7, I dont know how close the risk is to detonation. I wouldnt mind more torque, and more power in the real world useable rpm range of less than 6000 rpm. I think the hp will slightly increase maybe 5-10 hp, the torque will increase maybe 15 lbs, and the power curve will be stronger from idle up, and will cut off the max useable rpm by about 200 rpms. I also think the torque will peak at around 2800 instead of the stock 3000. It basically will look- on paper- more like that of a power curve of a small block V-8. The funny thing is that according to my owners manual, this ohc engine is almost as much power as the 5.0 engine. Only I like this one better.... except when i have to take it apart. :exp:

 

[gto78]

UPDATE:!
Job Finished! I put it together, it runs awesome, quieter and WAAAY smoother than it has ever run since 1998 when it was brand new when I got it. I am SOOOO pissed off at ford corp dealers (one in denver one one in stuart, FL) for blatently lieing to my wife about "NO RECALLS..." on that truck/engine. When she repeatedly brought it in for rough idle and stalling problems they were supposed to automatically perform the extended warranty recall on the intake gaskets (which i recently learned about)- - and THEN if that didnt work out they should look for other causes. INSTEAD they ripped her off for $1500 and replaced the fuel pump (TWICE) and got her for a battery, injector clean, throttle body clean (another TSB), computer upgrade, and a ton of other ****. After that it ran exactly the same. In fact it now stalls when making a left turn after long driving periods. We were almost literally killed in a head on collision because of that left turn stall problem.