Start up knock

[Flyman 27]

My '91 has always knocked a little upon startup. It fades away after a couple seconds. This year when I started it the knock was much louder & lasted much longer. Now it is doing the extra loud knock on all start ups.

I have had some experience with overhead cam engines and I would guess the problem to be cam chain slop. Either one or more chain guides are worn or broken.

Has anyone done this repair before? Any idea of cost?

Dan

[DRM500RUBYZR-1]

Which oil filter do you use?
and, please explain, deep knock or a metallic rattle?
Marty

[rush91]

My '91 has always had a second or so of rattle, but have noticed it goes away after an oil change. ( Amsoil and AC Delco PF970C ) Once I get around 1000 miles or so on the new oil change, the rattle slowly comes back.....

[DRM500RUBYZR-1]

Try the Bosch 3401 listed below and please report back if this changes it.


Bosch 3401 Premium FILTECH Oil Filter



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Exclusive FILTECH media technology screens out more harmful contaminants for greater engine protection
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[Flyman 27]

I use the WIX 51324, the HD filter with the silicone anti-drainback valve. They are supposed to be one of the highest rated filters for this engine.

[DRM500RUBYZR-1]

OK,
Rattle or KNOCK?

[Flyman 27]

Years ago I had a Lincoln with a 4.6L DOHC engine. It had a failed chain tensioner and the chain slapped against the housing upon startup.
What I am experiencing sounds like just like that.

I ordered the oil filter. It's worth a try.

[DRM500RUBYZR-1]

OK, that does sound like tensioner/ chain noise.
Which oil are you using?

[DRM500RUBYZR-1]

My '91 has always had a second or so of rattle, but have noticed it goes away after an oil change. ( Amsoil and AC Delco PF970C ) Once I get around 1000 miles or so on the new oil change, the rattle slowly comes back.....



Change to the Bosch filter now that it is doing it again after 1000 miles.
Just change the filter and let us know what happens.
Marty

[Demps]

If isolated to chain rattle at start up and if still somewhat present after new anti-drainback oil filter...this helps some:

https://www.jerrysgaskets.com/housing-rh-cam-chain-tensioner-2nd-design-90-95-1g4/

[Flyman 27]

I use Mobil 1 oil

[Flyman 27]

That tensioner from Jerry's looks promising. How much work is required to replace it? My back won't allow me to do much now-a-days, so I would have to pay to have it replaced.

[Demps]

That tensioner from Jerry's looks promising. How much work is required to replace it? My back won't allow me to do much now-a-days, so I would have to pay to have it replaced.

It’s sporty for a bad back.

Assuming it’s only/mostly oil pressure related: I’d wait on the oil filter. It’ll cure some. One of my cars (non-Dunn) has the tensioner upgrade & good filter but still rattles some until oil pressure builds.

Ted

[Flyman 27]

I'm not far from Mark Haibeck.

[Demps]

I'm not far from Mark Haibeck.

That’ll cure it all.

I would start simple and see if a good oil filter helps...then go from there.
Ted

[Flyman 27]

That’ll cure it all.

I would start simple and see if a good oil filter helps...then go from there.
Ted

I have a short video of a startup, but I can't figure out how to post it.

[Ccmano]

I have a short video of a startup, but I can't figure out how to post it.

Post it on YouTube then post a link here. Personally I wouldn’t be too worried about a little startup chain rattle. As already stated get a good filter, WIX 51324 is excellent and use 10-40 oil.

Mark Haibeck does an excellent job of explaining the situation.
http://www.zr1specialist.com/HAT%20Web/articles/Start-Up%20Engine%20Rattle.pdf

H
:cheers:

[Flyman 27]

If isolated to chain rattle at start up and if still somewhat present after new anti-drainback oil filter...this helps some:

https://www.jerrysgaskets.com/housing-rh-cam-chain-tensioner-2nd-design-90-95-1g4/

That new & improved tensioner from Jerry's is only $160. Mark just told me that he has a process worked out so that it only takes an hour to swap out the old tensioner! Now, that's a plan!

[spork2367]

I use the WIX 51324, the HD filter with the silicone anti-drainback valve. They are supposed to be one of the highest rated filters for this engine.

The WIX is one of the best filter options out there. Here is my post from 2013 when I tested it.

Before I saw that Mark had an update including the napa filter, I performed his test on mine. Mine held 11 oz after 8 hours 8 oz. (weight) of oil after 24 hours, consistent with what he found.

I've used napa gold filters on all my other vehicles for years. Wix (manufacturer) makes great filters.

http://www.zr1specialist.com/HAT%20Web/articles/Oil%20Filter%20Recommendation%20Update%202011.pdf

"Oil Filter Recommendation Update 2011
Recently we have observed that the anti-drain back valve in the Bosch 3401 filter is leaking. The filter looses most of the oil after the engine is off for 24 hours. This causes an approximately one second delay before the oil pressure builds at startup. This can add to the time that the right side camshaft chain rattle occurs. My current recommendation is for the ACDelco PF970C filter. We have found that it retains eight ounces of oil after the engine is off for 24 hours. Although the part number has a “C” in it like the original ZR-1 filter the color of the filter is blue. We also found that the NAPA 1324 filter retains eight ounces of oil after the engine is off for 24 hours. The filter is white in color and is made by WIX."


Marc also had an update about some Bosch filters leaking down:

http://www.zr1specialist.com/HAT%20Web/articles/Oil%20Filter%20Recommendation%20Update%202015.pdf

[Paul Workman]

Years ago I had a Lincoln with a 4.6L DOHC engine. It had a failed chain tensioner and the chain slapped against the housing upon startup.
What I am experiencing sounds like just like that.

I ordered the oil filter. It's worth a try.

Expertise: I suggest you buzz over to Marc's shop or Pete's shop. Let either of them listen to it and diagnose it...is what I have done once or twice.

[DRM500RUBYZR-1]

Many times, not all, but many, changing oil filter brands to ones that have in the past provided good oil retention often resolves the noisy right side tensioner issue.
I have never used the Wix filter, but if others have with good results, then certainly it should be fine.
I have seemed to always find each of the filters is a bit of a hit or miss chance of causing or eliminating the rattle.
I put a 970C on one car all is fine, another, rattle.
I often use the Mobil One Black filter. Never had an issue with it on my car.
Put one on a customer car...………. rattle.


I always suggest simply changing filters first to see if it can be eliminated, as filters are pretty inexpensive, and it takes 5 minutes.
Delco, Bosch, Mobil One have been my stand bys, but Wix sounds good also.


Try one, two, or three, just the filter, no need to mess with the oil other than topping it off.


If after two or three different filters, it has not improved, then you either live with it, or get the part From Jerry's and make it go away.


For over twenty years owners have often lived with it calling it normal. The two that I have owned only did it when left sitting for 2 or more months, so I never really gave it much thought.


If it is happening daily, AND getting louder, then yes, that suggests one take further steps if a filter change or two, does not improve it.


I will also order a Wix, and try it myself on the next one that comes in with that complaint.


Good luck and both posters keep us updated.


To the one that had it come back after 1000 miles, that would seem to suggest a lazy check valve, simply try a different one.


Marty