engine and drivetrain Knock Knock... Who's There? Knock Knock.

[Rocan]

I've always had the light come on at idle when warm. Less so with 20w50 (had 15w40 In there for a while). I'm aware it's a pressure light and not a level light. I'll check compression and oil pressure when my gauges come in and report back.

['76mintgrün'02]

I read a few of the reviews for the gauges you ordered and found this one:

" By Glenn Atkinson -

This review is from: OTC 5610 Transmission/Engine Oil Pressure Kit (Automotive)

The gauges are of adequate quality (although glass lens were a little loose), however for this to be useful to me it requires a M12*1.5 adapter. The kit includes several adapters.....just not the one that is required for BMW motorcycles, BMW cars, and many other European cars. This adapter size is not available in Canada. I've had to manufacture my own in order to use this tool.

Other than this gross oversight, the product worked well. "

[Rocan]

I read a few of the reviews for the gauges you ordered and found this one:

" By Glenn Atkinson -

This review is from: OTC 5610 Transmission/Engine Oil Pressure Kit (Automotive)

The gauges are of adequate quality (although glass lens were a little loose), however for this to be useful to me it requires a M12*1.5 adapter. The kit includes several adapters.....just not the one that is required for BMW motorcycles, BMW cars, and many other European cars. This adapter size is not available in Canada. I've had to manufacture my own in order to use this tool.

Other than this gross oversight, the product worked well. "

 

 

I saw that, but figured I could figure out some kind of adapter. hopefully its not too much trouble. 

 

found this...

 

http://www.amazon.com/Auto-Meter-2277-Electric-Temperature/dp/B000CIF3UM

 

bit expensive, but what do I do... Really odd that they include an m12x1.75 but not an m12x1.5. 

Edited September 18, 2013 by Rocan

[Buckeye]

Seems like you have had the oil light flickering for sometimes and perhaps is staying on more often and for longer period now. Try to find out status of the oil pump and the tension on oil pump chain.

[hip2B74-76]

Things to consider:

Piston slap when cold (loose clearance, forged pistons, wear?)

Failing sender (does it leak around the plastic part surrounding the spade terminal)

Idle speed (too low)

Fuel contaminated oil (how does it smell)

[hip2B74-76]

Oh as for the adapter, I remember buying a standard sized one that was slightly larger and using a tap and die to impart the correct metric threads. Couldn't find one locally and it was exorbitant to purchase online. Hasn't leaked in 10 years.

[dbmw2002]

20-50 castrol and a can of STP? works every time for me, wont fix it but if it still knocks it might be twice this year

[Rocan]

Idle speed and mixture is fine (I adjust it a couple times a year, just did my fall weather adjustment). Oil pressure light does not come on at all since going to 20-50 castrol except when revs drop below 800rpm. Motor runs a little rough when cold, but "fine" when warm, though an experienced mechanic would quickly notice that its very tired... it doesn't rev as freely as it should. 

 

I've had all covers and the head off this motor last winter when I replaced the head and replaced all the gaskets (didn't have money at the time to do a complete rebuild on the bottom end). Replaced the timing chain and guides and blew out whatever gunk was inside the oil passage ways and pan. I had noted that the oil pump could have used some shimming, but I didn't have shims or time to wait for shims at the time, and since it ran like that for so long without any issue it was "good enough". Bores were glazed over but undamaged, and I can't remember any play in the rods or bearings, though I wasn't particularly concerned with it at the time. 

 

 

I can't really decide if the loss in power I've been feeling is in my head or not; the engine runs very well with the megajolt on there. I have not been tempted to rev the motor much at all since the noise came back. What really confuses me is that its only there for a few seconds on a cold start. a warm restart (i assume with oil still not having drained completely) will not display the noise. 

 

Tools didn't arrive yet, so no hard data yet. 

 

EDIT: Just 5 minutes after I posted this tools arrived. Still have to wait for the m12x1.5 adapter, but I'll do a compression test tomorrow and report back. 

Edited September 19, 2013 by Rocan

[ray_]

Post an audio clip.

 

Castrol 20/50 eh? 

[Rocan]

Compression test:

Cyl1: 105

Cyl2: 115

Cyl3: 110

Cyl4: 115

So not too terrible. Oil pressure test should reveal a lot more.

Edited September 21, 2013 by Rocan

[Hans]

If the noise goes away fairly quickly, it may be piston slap. Not terminal, but might be related to compression being a bit low. Keep in mind that loose bearing clearances will not affect how an engine performs. At least until something lets go.

[Rocan]

I'm not ruling anything out at this point... you're absolutely right on all counts. 

 

I'm alright with loose bearing clearances and a little bit of noise, it's just the letting go part that worries me. I know the m10 is a very robust block, but it's hard to live with a clatter (however minor) while I'm putting 40 miles on the car every day, 5 days a week, plus the occasional weekend trip. 

[Hans]

You might be OK with loose clearances, but rod bearings will get worse and destroy the motor if one lets go. Mains might last a bit longer - I'm not familiar with how they eventually expire - other than perhaps destroying the crank. You'd need to pull the pan and Plasti-gauge all the bearings to find the culprit - unless it was obvious from bearing condition. I think Federal Mogul has a webpage of bearing pictures. I ran a Bavaria for some years that had piston slap on start-up. Pistons expand with heat to reduce clearances. Not so with bearings.

[Rocan]

Just did an oil pressure test... 

 

 

Warm Idle- 18psi, 15psi when a bit hotter.

Warm 2K RPM- 45psi

Warm 3k RPM- 65psi

Warm 4k RPM- 72psi

 

 

So, quite good. I'll be using this pump in the next motor since I know it's a good one, at least. 

 

I'm still at a loss as to what the cold start/no pressure knock is. I'm thinking cam chain tensioner, perhaps it needs to be primed again for god knows what reason? 

 

I think if it were a rod bearing it would be much more prevalent at speeds, though when driving around everything is a-ok.

 

Thoughts?

[ray_]

Did u pull individual plug wires and start?

 

Will you make an audio file and post it?

 

Am I typing for my own benefit? :-p