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Discussion Starter #1
Could use some advice. I've just finished re-ringing the pistons & changed the big end bearings while I was in there. Reassembling the top end, I noticed a seized inlet rocker, also missing its plastic cowl. On running the engine, all good apart from a tappy top end which I put down to the tappet. Today the tapping has become more pronounced & this evening,, the oil light has come on at idle. It goes out with a breath of throttle but obviously shouldn't be on at all. The engine is full of new oil I intended to run for a few hundred miles before changing. The light doesn't come om when cornering & only when it's warmed up.

Now I'm thinking oil starvation in the top end & want to get sorted quickly.
 

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Might be a good idea to get a gauge on it to test the pressure, or take the sump off again just to check the pickup is clear etc.? Definitely needs a new rocker.

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Discussion Starter #4
I've got a new rocker on order & I should say the cowl was found sat by a valve spring & I removed it before losing it in the garage somewhere, so I know it's not blocking anything. Is there any chance these things are coincidental? I've read that cheapy filters can collapse & that oil pressure switches can go a bit touchy with age.

Good shout on the pressure gauge, I'll definitely do that & while doing the big end bearings, I did remove & refit the pick up for access reasons. I can't honestly recall whther I saw an o-ring on the pipe joint & I'm wondering if it fell off without me noticing, even though that seems unlikely. Dropping the sump for a look seems sensible too.

As usual, when rebuilding, I was careful to ensure all the followers were correctly seated & sat directly over the valves as they should be.
 

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The pressure check is always advisable, although some people might just buy a sensor as it's an easy swap of a cheap item. It is normal for oil pressure to drop as the engine heats up but when the light is coming on with a hot engine it does suggest the pressure drop could too great or wasn't right when cold perhaps.

There is a seal on the pick up, if you took the pick up off and didn't notice the seal at all let alone renew it, then whether or not it's the problem you should check it imo. Some of the 'O' rings could be re-used perhaps but that is one location where you wouldn't really as it is above the oil height and vital that it's in good condition.

Several people have had sensor issues, likewise with the valve in the filter housing. Oil pressure after you've renewed the end shells should be better than before, the mains make a significant difference also. Have you had the timing cover off? If you have, was the crank damper lined up with the oil pump inner gear when refitted? The gears are brittle.
 

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Discussion Starter #6
Cheers CoB, all sound advice. Didn't take the timing cover off but at one point, I did manage to drop the timing chain down into the bottom of the chamber. I didn't think anything of it at the time & just fished it back out with a magnet tool & timed the engine by winding one to tdc & lining up the cam sprocket.

Because I can't remember seeing an o-ring on the pickup pipe, I think I should drop the sump soonish & check that out. Assuming I've managed to lose the o-ring, I guess it's possible oil is spilling out of the pipe joint & that could be a root cause.
 

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dropping the chain doesn't matter unless the bottom part of the oil pump/timing cover has already been smashed off during previous chain problems and not renewed. If the seal is damaged the pick up doesn't leak oil, it can just draw in air potentially. It may be ok of course but better to know, well I'd want to ;O)
 

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Discussion Starter #8
Ah right, makes sense. Just been out in it & no oil light this time but yep, I'll take the sump off & check the pick up before much longer, I want to know too! Lucky for me then that the HK amp has packed in (again) to take my mind off things :/
 

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Discussion Starter #9
Right, bit of bad news. I swapped the seized tappet for a working one & the tapping isn't cured. There's a pronounced tapping noise between 2 & 3k which I can make much louder feathering the throttle at that point in the rev range & I think now it's the bottom end knocking. I'm guessing that's the end of this engine & not sure what to do next given the value of the car.
 

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May still be a top end noise, have you have the sump off again to have a look?

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if it's 3k light throttle that's typical of ends be it small or big. If in doubt pull the sump, and take the caps off, if the crank looks good push the rod up a little to retrieve the top shell and it will reveal the wear perhaps, you could be lucky who knows, shells aren't expensive and OEM bolts are around £30, but if it's a scrapper just re-use the old ones, but I'd repair it.
 

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Discussion Starter #12
It's definitely big ends & the overwhelming likelihood is I've put a cap on the wrong way round. Would explain the oil light too. I popped in to see Tony at Minisport today & his advice was to drop the sump, have a look & change the bearings again as required & if that doesn't work, a junkyard engine is next. Dopey mistake to make, I was sure I had everything the right way round.
 

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the chances are if you've done that you may be able to reverse the error
 

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Discussion Starter #14
Thanks, certainly hope so. Had a talk about whether the cracked con rod would be compromised by misassembly & the general view was providing it hasn't been ragged, it should survive. I've a new set of bearings should be here tomorrow & we'll go from there.
 

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Here is an idea , some people change the oil filter and do not put the cartridge and spring back in , throwing the cartridge away mistakenly thinking it’s part of the old filter, this will cause low oil pressure
98348
 

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Discussion Starter #16
Dropped the sump again this morning. Sure enough, I found the bearing cap on No.3 fitted backwards. Remarkably, there is no damage to the journal that I can discern. I've fitted a new set of bearings across the board, checked the pick up (the seal is present) and I consider myself very fortunate indeed. Car runs smoothly again, no knocking, we'll see how it goes. Here's what I found on 3:

98408
 

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Here is an idea , some people change the oil filter and do not put the cartridge and spring back in , throwing the cartridge away mistakenly thinking it’s part of the old filter, this will cause low oil pressure View attachment 98348
I can't say that I've seen either of those parts before, which is odd as I've changed my oil every 2.5k miles for the last eight years
 

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Well done (y)

Dropped the sump again this morning. Sure enough, I found the bearing cap on No.3 fitted backwards. Remarkably, there is no damage to the journal that I can discern. I've fitted a new set of bearings across the board, checked the pick up (the seal is present) and I consider myself very fortunate indeed. Car runs smoothly again, no knocking, we'll see how it goes. Here's what I found on 3:

View attachment 98408
 

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Discussion Starter #20
On the oil filter spring & cage, it does show up om real oem but I think it was subject to a revision, but don't quote me on that. One other thing, I noticed a missing oil spray nozzle on No.1, I've ordered a replacement, do we think I'm ok to drive it for now? AIUI, the nozzle sprays the underside of the piston for cooling.
 
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