2200SC, unusual noise

robgee1964

robgee1964

Member
Hi

I'm posting this in the engine section, following my recent engine swap project.

Basically the new engine appears to run very well, the only thing is this strange noise, at idle/low revs. It's hard to describe, but sounds sort of half way between a tap and a squeak. Doesn't make the noise when the engine is stone cold, it comes on once its been running a few minutes. It disappears once the engine is revved up slightly.

It sounds internal to the engine, if I remove the oil filler cap it can definitely be heard from within. Also it sounds like its going at half engine speed (ie cam/dizzy speed).

Investigaton so far :-
1) I've pulled each plug lead off one by one, with the idea of eliminating little end knock. Noise is present regardless of which cylinder I disable in this way.
2) Had the rocker box off last night and checked condition of cam lobes, tappet buckets and chains. Can't see anything obviously untoward.
3) Naturally I've done an oil and filter change, its now got comma classic 20/50.

I've taken a short video of this and its on youtube (yes I know I need to get a life!!).
http://www.youtube.com/watch?v=WOBTVq-fpL8

It actually sounds louder in the video than it does in the flesh, must be something to do with the rubbishy mobile phone mic!

I'd be extremely grateful if anyone has any ideas as to what might be the cause. I don't really mind about it having a slight noise, just so long as its nothing serious!

Cheers,
Rob
 
It's tweeting! I've heard this noise from 4 cylinders many times before. But it is jolly loud with the oil filler cap off isn't it!

I presume you've checked tappet clearances? You are looking for tight ones rather than loose with this engine.

Chris
 
Hi Chris and thanks for your reply.

One of the chaps at work suspected a tight clearance somewhere. I should have mentioned in my post, I checked the clearances last night, they are all between 0.013-0.014".

As I say it does sound a fair bit louder in the video though, and its strange how it goes away as the engine speed rises?

Other than that everything seems fine, oil pressure is great and there's no rumbling bearings or smoke etc.
 
Check that the alignment tube in the inlet manifold isn't loose.

If you have those valve clearances on all cylinders that means all the inlets are too wide. If you had run the engine during the day when you checked the clearances in the evening you won't get accurate readings either.
 
Heard some thing similar on a Ford V4 back in the 70's which was a blown head gasket, compression forcing air out of the piston made a whistling sound, the gasket had gone on the outside, although sounds like it could be leaking into the crank.

A compression test would rule this out.
 
If it was me, I would check the valve clearances with the engine completely cold - like Harvey says, if correct, your inlet clearances are too big. The inlet clearance for a 2200 is 8-10 thou and exhaust is 13-15 thou. If your inlet clearances are up at 13-14 they are significantly out. If the clearances were 13-14 thou on a warm engine, I am guessing they would be even higher when cold, so they could be well out?

I think the valve clearnaces normally get too small with time on 4-cyl P6s (that's certainly what happened to mine). However, I just read through your thread and you said the new engine has had a rebuild. So, maybe it was set up with high clearances?

If the inlet valves are opening too late, this may cause residual exhaust gas to be in the cylinders when they start on the induction stroke? In other words the inlet/exhaust valve overlap is too small which can cause problems (and odd noises) especially at idle that go away at higher rev's.

Compression test is also another thing I would do. It's quite quick/easy and can tell you a lot.
 
Yes the inlet clearances are a bit wide, normally I'd have expected this to cause more of a chattering noise. However the point about the late inlet timing/valve overlap is an interesting one.

I've not done a compression test, it does run very evenly at all speeds. Nevertheless I will certainly check the compression, next time I've an assistant to hand. The strange thing is, the noise goes away when you rev the engine up. Also, now and then, its disappeared at all speeds for a few minutes. Whatever it is, its definitely at half engine speed and sounds more like its from the front of the engine, although its really hard to be sure. I did wonder if it could be related to the distributor drive at all?, or even cam for the fuel lift pump?

The thing is, I'm looking at it quite philosophically. Over the years I've had several good second hand engines, including a jag straight 6 and landrover turbo diesel, both of which would have cost a fortune to recondition. The only duffer I ever had was a ford pinto (and boy was it duff!), so really the overall balance is still in my favour. I've fitted the gearbox which came with this engine, and thats proved to be significantly quieter than my original, not to mention the clutch was like new also. So I'm not grumbling for 100 quid!

This engine still runs better than the tired TC unit, and it gives me time to rebuild the original engine, at my own pace. I've already got a set of pistons (which admittedly would need some machining work to lower the compression ratio). The TC also needs a bottom end rebuild, whilst the top end and timing chains should be quite reasonable, as there are receipts for timing chain and valve renewal in the history file. I'd like to find the source of this noise though, if I can prove the pistons/bottom end are OK then it gives me the option of fitting the TC head to this block, as a couple of people have already suggested.

Thanks once again for all the replies

Rob
 
Don't forget that hint about the sleeve in the inlet mnifold!

Pitty you've already got 2000 pistons. I really wouldn't get into machinig them or otherwisw modifying the crown. I'd offer two alternatives - either buy some 2200 pistons and bore the block to suit (2000 blocks will take boring to 2200). Or buy a set of 2200TC carbs and manifolds - they are 1 3/4 HIF's instead of 2" HS's. This might seem a regressive step, but the 2000TC is overcarburrettored at low rpm, so the smaller carbs give much better tractability and, importantly, tunability. This means you are much less likely to suffer pinking at low rpm. If you also get it rolling road tuned instead of just using the 2200 needles, then it will be possible to tweak the mixture via different needles so it definitely won't pink at high rpm. This shouldn't damage consumption, I'd expect you to get rather better in fact. And the performance at low speed will be much better with no damage to top end performance (twin HIF 6's are perfectly capable of looking after a 4.6, so a mere 2 ltr is no sweat - the 2" carbs are way ott). So not a lot of doubt which way I'd go - 10:1 2000 with HIF 6's.

Chris
 
chrisyork said:
Pitty you've already got 2000 pistons.
Chris
Click to expand...

I picked them up for a handy price a few years back, when walkers were closing down. They are the genuine AE item, so even if I never use them, I expect I can easily sell them on.

I'd appreciate a bit of help re this inlet manifold dowel thing though. Can you explain how a locating device of this type could make this noise, which is a distinct "chirp" at what sounds very much like half engine speed?
 
robgee1964 said:
I'd appreciate a bit of help re this inlet manifold dowel thing though. Can you explain how a locating device of this type could make this noise, which is a distinct "chirp" at what sounds very much like half engine speed?
Click to expand...

It's a tube that should be held by the carb insulator block, but it comes adrift and then gets dragged around by manifold depression.
 
Harvey thank you for that explanation, I really appreciate the help and advice.

However I'm becoming increasingly convinced that this engine is a good 'un. I've done a bit more work today, sorting out the choke cable properly, but the main thing I found was the ignition timing was significantly retarded. I've advanced it to 4 degrees BTDC static (BTW I really like the micrometer dizzy adjustment ....), which of course raised the idle speed so I've put that back to around 750 rpm. Naturally the engine runs a lot better on the road, BUT as an unexpected side effect this chirping noise seems to have all but vanished.

Just goes to show no matter how many years and how many old cars, there's always something comes along you've never seen before!

So onto the next project, which is the fitment of my pukka 1970's Lucas servoglide electric window kit, picked up unused from an autojumble a few years ago!

Cheers

Rob
 
robgee1964 said:
I've advanced it to 4 degrees BTDC static (BTW I really like the micrometer dizzy adjustment ....), which of course raised the idle speed so I've put that back to around 750 rpm. Naturally the engine runs a lot better on the road, BUT as an unexpected side effect this chirping noise seems to have all but vanished.
Click to expand...

Aren't 2200's (SC and TC) meant to be set at 8 degress BTDC?
 
If it's running straight unleaded, or unleaded and a basic additive, you wouldn't want to push it too far, all trial and error i guess with old engines and new fuels though.

The only thing that confuses me is how this would effect the noise, my only thought is that if it was really retarded then there would be all sorts going on in the chambers at times they shouldn't be, i.e. combustion with exhaust valves open etc....
 
darth sidious said:
Aren't 2200's (SC and TC) meant to be set at 8 degress BTDC?
Click to expand...

Your absolutely right I've mistakenly taken the figure for a 9:1 2000SC! However as pointed out I don't want to push things too far, I'll perhaps advance it some more, but a small amount at a time. There's certainly no hint of pinking at the moment, and thats on 95RON unleaded.
 
There has also been past discussion on the forum about the timing marks on the crank pulley on P6's being inaccurate. So, unless you know that your timing marks are properly calibrated against actual Top Dead Centre, is it fair to say that the figure you think you have it set to could be a little academic?
 
Well the way I see it, the acid test is how the engine drives and sounds. I may try dialling in a bit more advance and then turn it back if it shows any signs of pinking. Its running quite acceptably at present though.

Have many engines been found to have inaccurate pulley marks? I guess I could verify them by using the flywheel marks as a reference, unless they are wrong too?
 
JVY said:
There has also been past discussion on the forum about the timing marks on the crank pulley on P6's being inaccurate. So, unless you know that your timing marks are properly calibrated against actual Top Dead Centre, is it fair to say that the figure you think you have it set to could be a little academic?
Click to expand...

Ah, I thought that issue was on the V8's, not the 4-pots.

So in essence of that being so on the 4-pots too, the 'wrong' setting might be 'right' overall?! :shock:
 
If it helps, I think this was one of the threads I recalled that mention 4-cyl timing marks.

http://www.classicroverforum.com/viewtopic.php?f=2&t=9947&p=73955&hilit=timing+marks#p73955

If you wanted to check that your TDC timing mark is correct, there are different ways to do it (E.g. wooden dowel down no.1 spark hole). Also, with modern fuels that have a lower 95RON rating, they are going to tend to resist pinking less than the old 4 & 5 star. Therefore, it makes sense for the timing to be retarted a few degrees less than 8BTDC. I reckon that my timimg marks are good to +/- 0.5 degrees and keep my timing set at 8BTDC. However, I nearly always use Shell V-power (97RON) and add Castrol Valvemaster (LRP and octane booster). I have no idea to what value above 97RON the booster makes the fuel but this setup works fine for me on my 9:1 2200TC.
 
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