Engine Knock

[Graeme Remihana]

Hi Guys I have 3 AU's 1 1999 Fairlane V8, 1 !999 LTD 6, and 1 2000 LTD V8
The 2000 LTD has a light knock mainly noticable at idle and usually after a service. It sounds like a big end knock but is intermitent. It started at around 70,000k's now done 130,000k's but still about the same loudness. I took it to ford they heard it put it up on the hoist got under to listen and it stopped and thats how it is, sometimes it knocks sometimes it doesn't. The 99 V8 has done 105,000k's and if I listen real hard I can imagine that I hear the same knock occasionally. Has anyone else had this problem? This knock does go away after a few thousand k's after servicing. I suggested a different grade of oil but the powers that be tell me they are using the right stuff.

[stiddy]

I was going to say use a different oil.. what oil are they using at the moment?

I find Penrite HPR15 is very very good.. highly recommend the stuff, ford and most service places recommend 5w30 for these engines, I personally think this grade oil is just too thin.. hence the reason for me using PenriteHPR15.

[RG]

Even Penrite HPR 30 which is a 20w 60, that was reccomended to me by someone that used to work at the ford plant.

[stiddy]

HPR30 is toooo thick.. well depending on engine k's..

[Graeme Remihana]

Yeah thanks for that, forgot what grade they told me they used tried to find it on the bills to no avail. but I'll dump this lot and try your suggestion. Couple of times I tipped some STP down it's neck to shut it up.

[stiddy]

Let us know how it goes.. Id be interested to see if the thicker oil makes a difference.

It did with my car.. always had tappy start up, and it just didnt 'feel' right.. tried HPR15 and havent looked at anything else since.

[amiers]

got the same knock in mine,(00 fairlane v8) mine is only there when the car is warm and on idle. if i take the rpm up by 500 its gone.

[atec77]

Originally Posted by amiers

got the same knock in mine,(00 fairlane v8) mine is only there when the car is warm and on idle. if i take the rpm up by 500 its gone.

A lot of the older windsor used to "knock" usual thing was a sloppy piston skirt but they ran for years like that. ( I had both zc and zd that did this)

[amiers]

yes i have heard it before too. when i was younger and had a lot of GT's i noticed it in a few of them.

[XR6-VCT-2000]

If its a knocking sound , not a tapping sound , then i was gonna maybe suggest the bottom end bearings might be the culprit/worn. My old cleveland v8 used to do it badly (after thrashing it hard for a few years ), yet it still ran np for years like that until i sold it ... hehehehe. I just used thicker oil in the end and it shut it up alot .

[Graeme Remihana]

OK thanks guys will be dropping the oil tommorrow try something thicker. ....like EP 90 eh?

[james22]

Originally Posted by amiers

got the same knock in mine,(00 fairlane v8) mine is only there when the car is warm and on idle. if i take the rpm up by 500 its gone.

If the knocking dissapears when you increase rpm like that its a good chance you have worn camshaft lobes and rocker gear. Old v8 started doing it and i had it checked out

[OzJavelin]

My AU V8 does EXACTLY the same thing .. straight after servicing it knocks and carrys-on for the first thousand K's .. then "seems" to quieten down a bit. If I listen hard at idle I can sometimes (but it's not consistent) hear the knocking when hot; 2 mechanics have also heard it so I'm not going completely mad. Mine has only just started to do it when hot, so I'm just leaving it until it does it more consistently before I attempt diagnosis/rebuild.

If you find a real cause/cure, please advise!

BTW: I got cold/hot oil pressure check to rule out bigend bearings .. hot @idle was about 30psi and at RPM was 65psi .. sounded fine to me?