Engine Knock Merc 165HP - Help!!

[ziggy]

Re: Engine Knock Merc 165HP - Help!!

i think ya'll need to remove the dist. prior to the ft. push rod cover comeing off.....
i think ya've already kinda checked the lifters myself.

I've had it running with the valve covers off and eliminated any noise from the rockers.

ya could check again with a hearing hose to ea. individual rocker thus locateing a noisey lifter. another method notein in my sevice manual is to place a finger on the face of the valve spring retainer. if a lifter in not proper, a distinct shock will be felt when the vavle returns to its seat.....the way i'm gettin it from reading the service manual is that ya check lifters these ways. aslo states that if ya find one bad one, ya should rebuild all........i don't think ya bench test them.......

it does sound like yer knock is in the bottom end or the engine. i'm not the pro. but if the ujoint were bad in the drive. perhaps it's knocking. guess ya could try turning the drive hard over when it's makeing it's noise to help eliminate that idea......

use yer hearin hose to help locate the knock anywhere. it's a good diagnostic too for what it is. a piece of hose........

 

[Fishermark]

Re: Engine Knock Merc 165HP - Help!!

If and when you do pull out any lifters or push rods, be sure to mark them as to where they went, and keep them together. Even though any lifter will "fit" back in any hole, they wear in with a unique pattern to the cam - in other words be sure to put them back into the same hole! Otherwise you will be replacing them all with new ones shortly.

You don't need to worry about things falling out when you remove the cover - it will be pretty self expanatory when you remove it. But no, you will not be able to see the piston connecting rods through the side cover.

 

[Brooksie]

Re: Engine Knock Merc 165HP - Help!!

Very helpful to all - thank you.

Finding no signs of wear (and yes I have everything numbered for putting them back in order) I have decided to pull the motor.

I found water in my #2 cylinder due to a failed gasket - could that cause a loud knock? Perhaps it's what did the damage in the first place.

I see no signs of cracks 'anywhere' after very close inspection - will an old gasket that overheated create this problem?

In looking for cracks, I'm focussing on the cylinder wall and the head.

I think I'll take the head in for service and get a valve job done while I'm working on the lower end - unless you tell me that valve service is a piece of cake.

Please let me know on all these points - very much appreciated.

 

[SuperNova]

Re: Engine Knock Merc 165HP - Help!!

If you have a collapsed lifter you may not find any "signs of wear". The lifters fail internally. Try pressing them down with your finger or a piece of dowel, if you can push it down easily- there's your problem.
--
Stan