94 mtx top engine knock? With video link

[Cole maclachlan]

Hi guys

Here’s a doozy.

So I have a 1994 Ford Taurus SHO Mtx that has a top engine knock. it knocks more as the RPM is increased. I have taken a stethoscope to it and pinpointed the location not exactly but roughly.

I am now currently looking into nearby parts stores to see if they sell gasketsValves valves springs etc. etc. for when I do open the top end to investigate.

I have also taken off the maf and air intake just to investigate and when I had it running I noticed a bit of exhaust come out of the throttlebody so I’m leaning towards that it might be a valve lash possibly on the exhaust port maybe a loose valve spring or just a worn out valve spring. It could even possibly be piston slap on the valves itself and the top end.

I’m still new to these engines I do have an adequate amount of information in manuals to understand the tear down and rebuild butI thought I’d reach out to you guys to see what you guys might think of it. Maybe this is happened to you guys before.

I do have a video of it here is the link

If you guys have any tips tricks and or ideologies of what you might think this could be please let me know

Anything and Everything is much appreciated

Thanks in advance

 

[Irish Pride]

Sounds like you have a failed timing chain tensioner. Is the noise coming from the drivers side of the intake?

These engines are non interference so the piston is not contacting with the valve and if you had a broken spring the engine wouldn't be running right now. Pull the intake and valve covers and I'll bet that you will see what's wrong right away.

 

[rubydist]

and the good news is you can fix that without having to pull the heads off, if its just a timing chain tensioner failure.

 

[Cole maclachlan]

Front chain tentioner



Rear chain tentioner



Rear cams cylinders 4,5,6



Front cams cylinders 1,2,3

Sounds like you have a failed timing chain tensioner. Is the noise coming from the drivers side of the intake?

These engines are non interference so the piston is not contacting with the valve and if you had a broken spring the engine wouldn't be running right now. Pull the intake and valve covers and I'll bet that you will see what's wrong right away.

Thanks Irish

The noise was coming from the drivers firewall side/end. Mostly thinking it is coming from cylinders 5/6.

I have taken the intake manifold off and the valve cover to investigate.

As far as I can see is the isn’t anything obviously wrong with either the exhaust cams or the intake cams or anything else under the valve cover for that matter.

Everything was clean, tight, lubricatedand all looked fine.

I then proceeded to rotatate the engine manually from the crank to inspect the rotations and see if there were any obvious signs of damage or wear etc..

Everything thing looked perfectly normal

At this point I am having to dig deeper into the tool bag.

I think I’m going to try a leak down test
Do some more research on cam removal chain removal valve removal etc..etc..

Let me know what you guys think
Thanks again

 

[SHOdded]

How many miles on it? Have you checked oil and fuel pressure? No codes?

 

[rubydist]

I would be putting a borescope into the cylinders next. its also possible you have a cracked piston.

 

[Cole maclachlan]

How many miles on it? Have you checked oil and fuel pressure? No codes?

Close to 300k no codes

 

[Cole maclachlan]

I would be putting a borescope into the cylinders next. its also possible you have a cracked piston.

Thanks rubydist I will be doing that very soon

 

[Irish Pride]

Does the timing belt seem to be under proper tension? Does it look like the belt could have been slapping the inside of the timing cover?

 

[Cole maclachlan]

This tensioner seems to be a bit loose but not by much I think. I will look into the specs for tensioners. Also this one wasn’t near the location of the sound when I used a stethoscope. This was the front valve cover piston 1/2.

Does the timing belt seem to be under proper tension? Does it look like the belt could have been slapping the inside of the timing cover?

This is quite possible, I only have the range of a pry bar rotating the crank.
This is the rear cam chain cylinder 5/6 which has a different setup then the front and was pretty tight to the touch .

I still have to do some reading up on chain timing and replacement intervals for tensioners etc..

I will investigate more on any slapping marks or abrasions.

Also I will be attempting to remover the pan if possible to check the bottom out for filings sludge etc.

The manuals I have aren't too specific to this procedure.

Thanks again

 

[Irish Pride]

The timing chain tensioners are oil pressure activated so there will be some play in them with the engine not running.

The rear tensioner points down so you will need to remove the guide to get a good look at the tensioner.

 

[Cole maclachlan]

Hmm i guess I have to put it all together and run it to get oil pressure.
Is there an external gauge to read oil pressure? I mean I know I can get a cluster gauge for pressure but is there a tool for it?
Does it work like compression? Per cylinder?
Or oil pressure as a whole oil unit?
I have been told to try a leak down test and a compression test as well
I haven’t had a chance to remove the pan for investigation but I might do that soon

Thanks again

 

[SHOdded]

Usually, you remove the oil pressure switch and install a gauge to read oil pressure. Between 0-100 psi should be quite sufficient.

The pan is sealed with RTV, so be prepared for that. Timing tho as mentioned above sounds very likely at this point. If the idiot light for oil pressure was not blinking, you are probably ok in that department for now.

 

[BaySHO Performance]

I go with that rear timing chain tensioner. Unfortunately they are no longer available. Pistons are interchangeable between bodies.

 

[M Brown]

Hi guys

Here’s a doozy.

So I have a 1994 Ford Taurus SHO Mtx that has a top engine knock. it knocks more as the RPM is increased. I have taken a stethoscope to it and pinpointed the location not exactly but roughly.

I am now currently looking into nearby parts stores to see if they sell gasketsValves valves springs etc. etc. for when I do open the top end to investigate.

I have also taken off the maf and air intake just to investigate and when I had it running I noticed a bit of exhaust come out of the throttlebody so I’m leaning towards that it might be a valve lash possibly on the exhaust port maybe a loose valve spring or just a worn out valve spring. It could even possibly be piston slap on the valves itself and the top end.

I’m still new to these engines I do have an adequate amount of information in manuals to understand the tear down and rebuild butI thought I’d reach out to you guys to see what you guys might think of it. Maybe this is happened to you guys before.

I do have a video of it here is the link

If you guys have any tips tricks and or ideologies of what you might think this could be please let me know

Anything and Everything is much appreciated

Thanks in advance

I was looking at video on U Tube the sound it was making was close to what yours is doing and it turned out to be a rod bearing.

 

[BaySHO Performance]

Finally got around to listening to the video. Definitely not a chain tensioner that would rattle, not knock. Front tensioner fine: chain rivets well clear of guide, rear must be about the same. I second the rod knock.

 

[zoomlater]

Close to 300k no codes

If the car has this many miles, I would suspect rod bearings as well unless you know they were changed at some point

 

[Cole maclachlan]

Finally got around to listening to the video. Definitely not a chain tensioner that would rattle, not knock. Front tensioner fine: chain rivets well clear of guide, rear must be about the same. I second the rod knock.

Yeah nothing looked bad rubbing marks under the valve cover.

 

[Cole maclachlan]

If the car has this many miles, I would suspect rod bearings as well unless you know they were changed at some point

Unknown when anything was changed
Thank you

 

[Cole maclachlan]

Does the timing belt seem to be under proper tension? Does it look like the belt could have been slapping the inside of the timing cover?

Timing belt looked in great shape. No cuts marks or cracks. Had good tension as well.