knocking on start up

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kevin s
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knocking on start up

Postby kevin s » Thu Jan 07, 2021 7:38 pm

After our 1098 has been sitting for a few days for the first few seconds after it starts there is a noticeable bottom end knock / rumble. It starts virtually instantly even from cold, the oil pressure is good (40 psi at idle when hot), aside from a bit of timing chain rattle sounds fine at all times afterwards and has no major oil leaks. It seems like the oil is draining out of the galleries and pump when it is left standing, Anyone else seen this? I have a spin on oil filter conversion to fit and the filter supplied with it seems to have a one way valve anyone know if this is likely to improve things or is there something else wrong?

kevin

les
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Re: knocking on start up

Postby les » Thu Jan 07, 2021 9:04 pm

This is a similar issue, may help you.
viewtopic.php?f=4&t=73038


kevin s
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Re: knocking on start up

Postby kevin s » Thu Jan 07, 2021 9:18 pm

This is bit different in that after 4 or 5 seconds the oil pressure is up and it goes quiet so no problem priming, I was wondering if the oil can drain back into the sump through the filter pulling in air via the rockers etc. I really need a diagram of the oil circuit , from the description in the manual it seems to go sump filter, pump then into the galleries or relief valve.

oliver90owner
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Re: knocking on start up

Postby oliver90owner » Thu Jan 07, 2021 10:59 pm

Guessing that it is the centre main that is worst and the other two are past their best. Likely time for a crank regrind, I would think. Remove sump and check that bearing, is what I would be doing.

A short term repair might be a polish and new bearing shells if you are lucky.

Edited to add that the valve in the spin-on filters is a bypass to allow lube even if the filter is blocked

kennatt
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Re: knocking on start up

Postby kennatt » Fri Jan 08, 2021 8:48 am

Commonly known as the death rattle..........as you suggest caused mainly by wear in the bearings which lets the oil drain back into the sump when stood for for a long time ,if left it will gradually do the same even after a short lay up,each time it knocks causes a bit more wear etc etc.If you dont yet want to pull the engine for a re build,rig up a switch in the ignition side (Feed or return to coil would be easy) then when left to stand,spin the engine over to get the oil pressure up then flick switch to start. Had the same problem on a ser 11 some years back,but with the pull type solenoid you could spin the engine before switching the ignition on,delayed my rebuild for about 3 years But will need attention eventually. Good luck.

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Re: knocking on start up

Postby Nickol » Fri Jan 08, 2021 9:45 am

Also had the same problem (albeit on my Triumph Herald) together with a rumble/ sort of pinking sound, with only the slightest acceleration attempt running at 70kmh . Cutting a long story short from all the other things I did, I had the crank reground and this totally eliminated the noise and led to solid oil pressure readings, e.g ca 50psi when warm on idle.
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kevin s
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Re: knocking on start up

Postby kevin s » Mon Jan 11, 2021 6:47 pm

We'll see how it goes, at the moment it only makes the noise for a couple of seconds when it has been standing for a couple of weeks, the hot idle oil pressure is around the 50psi mark and it pulls like a train, the filter conversion I've got does have a one way valve so it'll be interesting to see if this has any effect. I also wonder if the A+ ignition is part of the problem, it used to take a few seconds to start and now it fires up first compression to hit tdc, we have found cranking it with no choke for a couple of seconds then pulling the choke out stops the noise as well.

When I get a chance I might dig out the spare engine which has got water in the crankcase to see if it's re-buildable, quite fancy building a supercharged engine.

liammonty
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Re: knocking on start up

Postby liammonty » Tue Jan 12, 2021 10:04 am

Hot oil pressure sounds fantastic - it's probably worth checking the gauge just to be sure it's genuinely that good. It seems hard to believe that there's serious wear in the bearings if it's the case.

I don't think that a non-return valve on the oil filter will make any difference. On an engine like the Triumph one mentioned above, they do, as the filter is mounted horizontally and it drains. On the Minor, though, the standard set up can't drain as it sits upright. So I suspect that the cause of the rattle on start up is something other than oil starvation caused by the filter.

kennatt
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Re: knocking on start up

Postby kennatt » Tue Jan 12, 2021 10:30 am

(we have found cranking it with no choke for a couple of seconds then pulling the choke out stops the noise as well.) exactly like fitting an ignition isolator switch.

oliver90owner
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Re: knocking on start up

Postby oliver90owner » Tue Jan 12, 2021 11:48 am

It’s not going to get any better if it is worn bearings. Fix it, or it is likely to cost a lot more or even scrap the engine.

Read kennatt’s earlier post (on Friday).

kevin s
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Re: knocking on start up

Postby kevin s » Tue Jan 12, 2021 9:04 pm

oliver90owner wrote:
Tue Jan 12, 2021 11:48 am
It’s not going to get any better if it is worn bearings. Fix it, or it is likely to cost a lot more or even scrap the engine.

Read kennatt’s earlier post (on Friday).
To be honest it wouldn't be the end of the world if it did it cost £100 and has done a couple of years with no problems, we have a couple of spares to rebuild. It's my 18 year old sons car now he is quite keen on something like a supercharged A series, a Suzuki engine or perhaps even going electric eventually.

He's doing a degree in mechanical engineering so it will all be good practice (and I've built plenty of Ford, Triumph Lotus and Rover v8 engines (some of which even still work!)over the years to guide him)

kevin s
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Re: knocking on start up

Postby kevin s » Sun Feb 21, 2021 9:19 pm

Well things seem to have deteriorated, it's got hardly any oil pressure at idle and even when you rev it it seems to fairly quickly rise to 25psi at around 1500rpm but then won't go any higher.

There are no knocking noises though.

My thoughts are firstly to look at the oil pressure relief valve on the off chance this is sticking or the spring broken, if that fails drop the sump and have a look at the bearings.

All this I suspect is heading towards dropping the engine out and fitting a new oil pump, crank / bearings and a duplex timing chain, we have a 4 post lift with an overhead crane, does anyone know if the engine and gearbox will drop out the bottom of the car with the manifolds and mounts removed, this would be the easiest way for us if it's possible.

Not the end of the world, least parts are cheap and It will be good learning for Andrew.

Kev

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philthehill
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Re: knocking on start up

Postby philthehill » Mon Feb 22, 2021 8:28 am

The engine will not drop out through the bottom of the engine bay. It has to come forward to clear the gearbox first motion shaft and then lift up and out.
The engine can be removed without removing the front panel but you must remove the radiator. Pull the engine forward to clear the gearbox bell housing and then turn the engine through 90 degrees and lift up and out.


MikeNash
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Re: knocking on start up

Postby MikeNash » Mon Feb 22, 2021 12:05 pm

I see that Kevin S is in the "Minor Addict" class so I definitely wish to "teach not a parent's mother to extract the embryo juices of an egg by suction", but that said, I hope as Liammonty recommended that you've checked the accuracy of the oil pressure gauge. I repeat this 'cos my previous engine could only struggle up to 42 psi (on a checked non-electric capillary Smith's gauge) when really hot (i.e. 85 - 100C read from a capillary sump gauge) and then only gave 8 psi at the idle when the oil warning light might flicker. However, that engine was mechanically reasonably quiet and went very well, cruising at 60+ (GPS read) as long as you like. (I changed the engine due high oil consumption! Circa 90 miles to the pint at high speed.)
"A Series" engines are tough and in my experience the odd noise in old age can be tolerated. I wouldn't want Kevin Junior to learn the hard way that he should be very certain of his data before the crucial decisions are made.
Regards from MikeN.
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kevin s
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Re: knocking on start up

Postby kevin s » Mon Feb 22, 2021 12:49 pm

The gauge is a capillary type and was working fine before Xmas, the oil pressure light is also coming on so I suspect the issue is real, the strange thing is how quickly this has come on, before xmas it was showing 40-50 psi at a hot idle now it's virtually nothing, in my experience bearings etc tend to wear gradually over a much longer time, it would be lovely if it was just the relief valve, I'll try to take it out this evening, otherwise I suspect something has come loose like the pick up or something has broken in the pump.

The other thing is we don't know the history of the engine, it was bought cheap as a stop gap so doesn't owe us anything, it had supposedly been re-conditioned at some point and looking thought the plug holes had shiny pistons and what looked like freshly honed bores and has a consistent 150psi compression, the timing chain rattles quite heavily though and the oil in the sump was far from new, so if it isn't something simple like the relief valve it may be worth stripping it and seeing what exactly is inside, he's doing a mechanical engineering degree so it would be good experience anyway!.

Cost wise parts are surprisingly cheap, the last engine work I did was on my Elan a head gasket was £50, cam followers £40 each etc, £15 for a full gasket set for a minor was a pleasant suprise! (not much else to spend our money on at the moment anyway).

Just hope it doesn't end up like the rover V8 in my TR it had a strange knocking noise when warm, which after 4 rebuilds turned out to be something to do with the block (suspected a loose liner when hot) I lost my sense of humour over that!

I was planning to drop it out with the gearbox (detents seem non existent in a couple of gears so we want to have a look at that too) and thinking back I know this works as I took the original engine out this way so plan is prop off, rear x member off, disconnect clutch, remove gearstick, head / manifolds, alternator and front engine mounts then drop the whole lot down onto a trolley.

Also not sure how best to mount the engine on my stand, usually it bolts too the bellhousing bolts but I'm going to need to take the backplate off get to the oil pump I'm thinking it may be best on it's side on a bench.

He did think about a re-con engine but in the long run he'd like a bit more power so is thinking about a 1275 or a suzuki 1.3, so for now we just want to get the 1098 reliable for a year or 2 until his insurance costs drop a bit.

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philthehill
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Re: knocking on start up

Postby philthehill » Mon Feb 22, 2021 3:47 pm

You can mount the 'A' Series engine sideways by utilising the dynamo mount bracket threads and the oil filter housing threads. Both sets of threads go directly into the block. You may need to reverse the engine stand mount brackets and/or drill additional holes in the mount brackets.
Or you can use a special adapter mount:-

https://www.ebay.co.uk/itm/Mini-A-And-A ... Sw5cJarCrh


kevin s
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Re: knocking on start up

Postby kevin s » Mon Feb 22, 2021 4:07 pm

Thanks, my engine stand is an upturned mk1 Cortina strut (shows how long ago I made it) welded to frame with a bolt through the calliper hole to lock into the disc, engine then mounts on the 4 wheel studs via a bracket, looks easy enough to make a bracket to bolt on those locations.

kevin s
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Re: knocking on start up

Postby kevin s » Tue Feb 23, 2021 12:38 pm

Pulled the pressure relief valve out today, firstly knocked up a tool to get it out without removing the starter, a spare 1 inch socket cut down and welded to a old 1/2" extension.
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with this it came out easily, everything looked fine, the spring is 70mm long which is is a couple of mm short but not enough to cause this.
rps20210223_121936 (002).jpg
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no difference afterwards, even cold it's got very little oil pressure and it's strange it fluctuates quite noticeably between 0 and 20 psi with a constant RPM, I am pretty sure it's not the gauge because every time it drops near zero the light comes on too.

still sounds fine, only noises are the timing chain and tappets which it has always done.

I am beginning to wonder if a vane in the pump has jammed or broken, so I think we will be dropping the engine and gearbox out on Saturday reckon it should only take a couple of hours, it was only put together a couple of years ago so there shouldn't be any great issues.

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philthehill
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Re: knocking on start up

Postby philthehill » Tue Feb 23, 2021 1:45 pm

What is the condition of the plunger that actually controls the oil pressure? The plungers are prone to picking up and jamming.
You can always fit a 5/8" ball bearing which is a well known and well used modification. The ball bearing will seal and most importantly not jam. http://www.minispares.com/product/Class ... o%20search
If it has a vane type pump I would recommend that you replace it with a concentric rotor type pump which is a much more efficient pump.
http://www.minispares.com/product/Class ... o%20search


kevin s
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Re: knocking on start up

Postby kevin s » Tue Feb 23, 2021 5:49 pm

The plunger had a bit of light scuffing but slid out and back in smoothly enough I have ordered the one you mentioned thanks, I'll put that in when it goes back together. I've no idea what pump is in there, as I've read further through the manual I realised they had about 4 goes at getting the pump right, the engine number is from 1970 so it should be the late concentric rotor one. This is one of the reasons I'm just going to take it out and strip it down, then at least we will know what is in there and have some faith in it being reliable.

I thought if anything it would be the gearbox which gave problems, it sounds like a bag of spanners in first (I think the previous owner clobbered the teeth more than a few times) but there are no signs of deterioration there at all, if anything it's got quieter as it's been used more.


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