making diesel noise

[roscoepet]

i just did the valve shim adjustment hoping the diesel noise would go away but it didn't. i keep reading about the cam chain tensioner. the plastic guide that is mentioned in the forum is that the tensioner or is it the whole assy. how many hours work to replace and any special tools needed? how easy is this to do. should i mess with the rod bearings instead? have never worked on cams or chains before. the good thing was i got back some lost power with some shims out of specs.

 

[Denny]

The bearings! BEARINGS!!! My SHO sounded like a loud Powerjoke Diesal when it ran last...
frown

 

[gosho89]

In regards to the chain tensioners, obvouisly I'm not getting any feedback on my postings apparently no one seems to know if the tensioners can be replaced without removing the cams. I have sent a few personal e-mail's to a couple of known sho tech's on this issue. I know that no special tools are needed, the SHO manual's only instructions are installing them while installing the cams at the same time. I have an extra engine on my garage floor, so I plan on spending sometime today trying to remove the tensioner with just the four bolts mounting it down. On the issue if the noise totally is the tensioners I will keep you posted I can't give you any feedback on the outcome right away since the car is 2.5 hours away and do to scheduling it looks like Dec 21st before I will be doing the repair. I was assuming rod bearings were the problem when I first heard the noise and also since this car had been run on extented oil change intervals (5k with regular dyno oil). This lasted until I notice the tensioner was missing its plastic strip and the chain had been riding metal against metal. So step one is to replace the tensioners and then if the noise still continues we'll move on to step two installing rod bearing. If you don't hear back from me-pop me an e-mail

<small>[ December 08, 2002, 12:10 PM: Message edited by: gosho89 ]</small>

 

[roscoepet]

thanks for the info kerry, i will be looking forward to your results.

 

[pjtoledo]

Just looked at a set of heads in the basement, looks easy enough to replace the chain tensioners. The cams will jump and rotate because of spring pressure, so be sure to measure and mark them first. The main timing belt will hold the intake cams steady, looks like you would remove the exhaust sprocket and lift it and the tensioner out together. Start by rotating the engine to get the cam bolts lined up with the head surface, there are alignment flats near the inside of the back bearings that should be perpendicular to the head. Use a 26mm or 1 1/16" wrench to rotate the exhaust cam to remove tension and re align it. At least 2 wrenches will be needed as the cam will pin the wrench against the head. An extra set of hands will be helpful as you will need to hold the EX cam in position while the chain and tensioner are installed. The usual precautions of proper torque and Lock-Tite apply.

Perry Toledo,Ohio

 

[DavidT]

gosho,
Why did you assume it was the rod bearings? Is the noise coming from the bottom?

 

[gosho89]

Thanks Perry,

I read your message then went out and did the inspection on my extra engine. That procedure should work. I will need to borrow a 26mm or 1 1/16" wrench from my work. I went ahead and adjusted the valves while I examined the tensioner procedure, its been something I've been meaning to do. Can't believe I found a intake set at .015 took a 2675 to get it to .008

dkautumna, I was assuming that rod bearings would be the most likely failure, I hadn't ran across a bad tensioners before. The noise didn't sound deep in the motor but I hadn't heard a bad tensioner before. Once I replace the tensioners later this month I will know for sure.

 

[roscoepet]

thanks for the continued effort. when i did my shims yesterday, i had several shims in spec but toward end of allowable. but the big news was i had two shims on exhaust cam on rear band that were out of spec. i am so glad i did the shims, if not disappointed that the noise remains. got back in the car today and it felt like a whole new car. had problems with traction with all my new found power. felt like a rookie on a 5-speed all over again.

 

[gosho89]

Update on tensioner replacement: Sorry to report that the bad chain tensioner was not the only problem with the engine. After completeing the replacement of the tensioner and buttoning up the motor, it was start and for about 4 minutes everthing sounded great, but then the clattering returned this time the sound bounced from one area to another until it was continously all over the top end. Shortly after the oil pressure light came on. My only expaination is the motor is starved of oil either plug oil passages from depris or a bad oil pump. See the owner had been using Pennzoil at 5k oil change intervals (bad, bad, bad) the motor was ulta sludge. I've advised him to drop the pan and look for clues, if he's lucky it maybe just a block pick-up tube screen and he should also count on replacing the rod bearings. Worst case is oil pump replacement, which will be unfortunate since he has just recently had the front 60k service done. This is one wounded motor!

<small>[ December 22, 2002, 01:30 PM: Message edited by: gosho89 ]</small>

 

[DavidT]

thanks for the update.
I wish I wasn't such a novice... Otherwise I would've already dropped the oil pan and done the rod bearings (also I would have removed the valve covers, etc. to inspect the tensioners). The deisel noise is very sporaidic in my sho. Last night it did it a lot, and very severe!
Im thinking you are on MY right track when you say blocked oil passages, I dunno though.

I installed a mech. oil pressure guage. What kind of readings would I be getting if the oil pump was going out, OR if I had blocked oil passages?
This is the ONLY reason I am considering buying a beat up 91 w/ 175,000 miles. The engine sounds smooth as silk.
Not that I could perform a swap

 

[DavidT]

wait a second.
if the rod bearings are shot, wouldn't the noise be consistent and persistent?

 

[gosho89]

Personally if it was my engine with the valve train issue, I would have replaced both tensioners and chains. I left the choice up to him on the repair. I only suggested he plan on replacing the bearings based on the fact the engine has had some oil pressure issues and thats the fastest way to destroy bearings. Keep in mind I was only hired to do the valve adjustment and had only planned on traveling (5 hours round trip) to his house on one weekend not two. Heck I've got a fresh quaife equiped trans and new clutch to install in my own car along with rod bearing replacement, upgraded motor mounts and somemore suspension upgrades before the end of January. I don't need anyone elses projects at this time, he is going to hook up with a local ford tech that has been suggested by another club member in the area to do the final anyalist and repair.

I've read were at idle you can have as low as 25psi. I'm use to ford V-8 with high volumn oil pumps with at least 40psi at idle.

 

[ILLSHOU]

Im having the same exact problem, (see noise/oil light) When i recieved replies to my post everyone said rod bearings...Now after reading this I guess it could be valve shims, blocked oil passages, bad oil pump, chain tensioners, man thats pretty broad...any way to narrow that down or does all of the above need to be checked?

 

[gosho89]

If you have the oil light on, its unlikly the shims or tensioner is the root cause of the problem. You may need to check them for damage (from lack of oil), but I would start with the botttom end. If you have more then 150k miles on the car the bearings may be the cause, because extreme wear on the bearings has caused excesive clearance and dropped the oil pressure. Thats one possiblility.

When I went to work on this engine I was never told about an oil light coming on. If the oil is not getting to the valve train it will be very noisey, plus the rods and mains are taking a beating.

<small>[ December 22, 2002, 08:25 PM: Message edited by: gosho89 ]</small>

 

[DavidT]

uh oh, I'm getting anywhere from 12-20 (usually after the engine is warm, it reads 12-15 psi) psi at idle. Is this bad? What are you other guys getting?

 

[pjtoledo]

dkautumna:
uh oh, I'm getting anywhere from 12-20 (usually after the engine is warm, it reads 12-15 psi) psi at idle. Is this bad? What are you other guys getting?

From the Helms manual,,oil pressure,,hot idling,,minimun 12.8 lbs. Thats all it says. Expect to see about 40 PSI if revved over 1500-2000 RPM. On a cold start, a lot higher. 3.0 and 3.2 same pressure specs.

Perry Toledo,Ohio

 

[DavidT]

ok, thats about what I get. SO am I in the clear as far as worn rod bearings?
What readings would you get for that? How about blocked oil passages? Etc...
Thanks!

 

[ILLSHOU]

the car only has 67,000 miles....

 

[gosho89]

The engine shouldn't have any of these problems with only 67k miles, don't know what to tell you. Someone will need to take a look at it to figure it out. Sorry not much help

 

[ILLSHOU]

yea thats what i thought, but i think it may have had a hard life. It was a repo. I dropped it at the mechanic today, as soon as i get word from him on what it is ill keep ya posted. Although it shouldnt have any of these problems with this miles, it may...I know there is defenitely some type of oil pressure issue...