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Loud whine and won't idle


rmorrow

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On my last run out, once the car had properly warmed up, it suddenly developed a loud 'whine' noise and stalled every time I went down to idle. I got it home and had a bit of a listen - seemed to be coming from the front of the engine but not the usual belt whine noise. I didn't want to leave it running for long so I haven't really investigated thoroughly. Started again from cold today and had the same issue after a minute or two and again the car won't idle. Seems to me like there's something causing some high friction. What are the most likely culprits? Water pump? Alternator?

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Yes and yes.

I'd suggest warm the engine by running it, moving the engine over by hand noting how much force it takes then remove the two V belts and rotate the engine by hand again. If it's noticeably easier to move then you just need to establish which belt causes the extra load, if it's the same then you're looking at something more fundamental to the engine.

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Thanks Andy

Is the timing belt tensioner bearing another possibility? I put in a new one less than 200 miles ago, but the timing belt has possibly been running a bit tight. Could this put high load on the bearing and cause this kind of issue?

By the way, I only have one vee-belt running the alternator and water pump.

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Yes, tensioner is an option, for obvious reasons it's not a good idea to turn the engine over with that off but would be a sensible next step if the V belt removal is not producing the correct change in resistance.

Running any bearing with excessive load is not great, even more so for a tensioner that runs on the reverse of the timing belt. If that was over-tight you really should replace tensioner and belt whether that is the issue or not, ideally check tension with a suitable gauge before removing it.

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remove the two V belts and rotate the engine by hand again. If it's noticeably easier to move then you just need to establish which belt causes the extra load,

Once you've removed the belts you'll be able to spin the alternator & water pump, & air con compressor if it has one, easily by hand and any problems with one of them will be immediately obvious. :thumbup:

Cheers,

John W

http://jonwatkins.co.uk

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So I whipped off the vee-belt but the alternator and water pump pulleys seem to be spinning OK. Next was the tensioner bearing. I was fairly convinced this would be the problem but again it seems to be running freely with no noticeable play or unusual noise. What I did spot though was that the earth strap has been damaged. Could that have got trapped between the bearing and the crank pulley and caused some friction? (Seems like a long shot to me...)

tensioner-earth-strap.jpg

Should I replace the bearing anyway?

The other possibility, based on the comment from Travis, is that the brake boost hose looks like it may have split. Could this cause enough of a leak to produce a loud whistle and cause the engine to stall? Again, seems unlikely, but I'll do a quick repair with some silicon tape and test again...

split-brake-servo-hose.jpg

If these aren't the causes, I'm worried there's something more fundamentally wrong...

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The earth lead could well cause the whining noise, rubbing on the timing belt; but that isn't going to make the engine stall. A hole in the vacuum system could also make a racket...and it could well result in the engine stalling, too. If you still have problems, then try listening to the engine whilst it's making the noise ... beg, borrow or steal a mechanical stethoscope if you can... or nip into Machine Mart and buy one, they're a great piece of kit. You can always extemporise one using a long screwdriver.....touch the blade on where you want to listen, and put your ear to the handle (with your thumb between ear and handle if thumb is cleaner than handle!). Whichever way, you will hear much more clearly...and can isolate exactly where the noise is coming from. My brother once bought a cheap Mercedes with a "noisy timing chain"...hence cheap...that, after the stethoscope diagnosis, turned out to be a rattling mounting for the alternator.....cured by wrapping the bush with tape!

Scientists investigate that which already is; Engineers create that which has never been." - Albert Einstein

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Brian's got the right idea...circumcise the hose and stick it back on again, see what happens!

Scientists investigate that which already is; Engineers create that which has never been." - Albert Einstein

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Hi all

So the hose has been trimmed back and reattached and now the engine seems to be running fine. But still got the squealing noise. First, I noticed that the vee belt was running around the front of the water pump pulley rather than in the groove!! :blush:

I was convinced that would be it, but with the belt back correctly, the noise was still there. It seems to be generally coming from the vee belt - can't seem to isolate it to one distinct area. Can you use a stethoscope / screwdriver on spinning components? Maybe it;s just that the vee belt is shot now and I should try replacing it?

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Have you still got the old tensioner bearing? If so I would be tempted to try that and see if the noise disappears. Just because it is new doesn't mean that it cannot be causing the noise, I changed one a couple of years ago for it to then fall apart 200 miles later.

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A loose belt can make an awful squealing noise...but usually only under load; power steering belts often exhibit this, when you wind on the steering. How tight are your v-belts? Using a stethoscope on rotating components is asking for serious injury! However, using one on the body of the device..waterpump, alternator etc. can give good clues. Your noise could be waterpump or alternator bearings...stick the stethoscope close to the pulley, then you can hear the bearings.... Putting on a new v belt can't hurt, but it's fiddly...as you already know!!

Edited by molemot

Scientists investigate that which already is; Engineers create that which has never been." - Albert Einstein

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  • 3 weeks later...

So, more problems...

I whipped off the vee belt (runs water pump and alternator) and started the engine. Noise was still there. So I was then convinced it was the tensioner bearing (even though I'd had this off before and thought it was OK!). When I did remove it this time, there was a fairly noticeable squeak when I leaned on the bearing and rolled it with my hand. Last time, I hadn't tried to add a bit of side load, so that's probably why I missed it. But anyway, I was fairly relieved as this is a much simpler and cheaper fix than a new water pump or alternator. So, with a brand new bearing fitted, I turned the key with fingers crossed......... but the engine wouldn't fire!! I checked for loose wires, voltage at the distributor and finally took out a spark plug and tested that - all fine. The fuel pump is clicking as normal, so I've got both spark and fuel. Engine was set to TDC and the distributor pulley is already marked up from previous belt tensioner changes so I'm confident that's gone back together correctly. What have I missed???

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Hi Rich

Yes, everything was set to TDC before I removed the belt and was in the same position when I put it back...

Even if the timing was out a bit, the engine would at least attempt to fire, I think. At the moment, it's just spinning on the starter motor without even a hint of combustion.

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  • Gold FFM

So, if everything is indeed lined up correctly, and you have fuel and spark, then I'd suggest whipping the dizzy cap off to check 2 things: a) is it rotating when the engine cranks; and b) is it pointing towards no. 1 at TDC.

British Fart to Florida, Nude to New York, Dunce to Denmark, Numpty to Newfoundland.  And Shitfaced Silly Sod to Sweden.

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Daft suggestion no. 1...have you got all the plug leads on the right plugs? Check the rotor position as Sparky says and then ensure that all the plug leads from the cap go to the right plugs.

Daft suggestion no. 2...check the fuel pump cutoff crash switch. Red bit should be down and the electrical plug in the bottom secure.

I know you've done this already, but yer niver knaw....

Scientists investigate that which already is; Engineers create that which has never been." - Albert Einstein

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So, if everything is indeed lined up correctly, and you have fuel and spark, then I'd suggest whipping the dizzy cap off to check 2 things: a) is it rotating when the engine cranks; and b) is it pointing towards no. 1 at TDC.

I assume it's rotating as I had no.4 plug out and it was sparking regularly with the engine cranking. But I'll check again and make sure it's in the right position.

Daft suggestion no. 2...check the fuel pump cutoff crash switch. Red bit should be down and the electrical plug in the bottom secure.

Not sure my car has got one of those - weren't they just on Federal cars?

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Are you getting fuel on the plugs when they are in the normal position? Iif not then it's either fuel not getting to the carbs or fuel / air mix not being pushed into the cylinders.

The latter hints at timing, either cam or dissy. I changed a tensioner bearing and was sure nothing had moved but after ages of trying to sort out why it wouldn't fire I found a cam had lumped over just by the force the valve springs exert, worth checking all the alignment marks again.

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My 82 Turbo has the fuel pump cutout inertia switch. When my cambelt broke, several days into my ownership, all was fine after I replaced it...no other damage....but the car ran for about 5 seconds and then stopped. Mucho investigation into timing etc. (which managed to drop the distributor back too far and disengage the drive!) and finally it turned out out be the plug connection into the inertia switch wot I had inadvertantly dislodged with the size 10 boot...plugged it back in, fuel got to the carbs and all was again hunky dory!!

Scientists investigate that which already is; Engineers create that which has never been." - Albert Einstein

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Oh dear. Had a look today and it seems the timing isn't right at all. :blush: Don't know how it happened, but it looks like it's almost exactly 180 deg out. At TDC on the flywheel, the dots on the cam sprockets are in line but pointing out instead of in! The only thing I can think of is that I had the crank pulley off to check it was OK and maybe I tightened that up while the belt was off, but I really don't think I would have done that, so I'm very confused. Anyway, I've obviously cranked the engine over lots but when I turn it by hand there doesn't seem to be any resistance. Is there any chance I could have got away without bending valves? Is it possible to get it back to the right position without taking the cam carriers off? At least then I could do a compression test....

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OK, even more embarassed now!

But with the flywheel spun round one more time, the cam sprocket dots are out by 3 or 4 teeth, so there's definitely a timing issue. Is that enough to stop the engine firing? And is it small enough I can just correct it by leaving the engine at TDC, removing the belt and rotating the cams back?

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If that's the cam timing....how's the ignition timing??? Sounds like you can't trust anything. Check you have TDC by the screwdriver-down-No1-plughole trick. Then take the top off the distributor and see where the rotor is pointing. I'll bet you have the ignition timing 180 degrees out, too....since you had the valve timing wrong, it's very likely that you were on the wrong stroke when you set it up...so it wouldn't be getting any sparks in any of the right cylinders!! As for the inaccurate valve timing.....you would probably get away with taking the belt off and moving the cams into correct alignment, then fitting the belt (very carefully, it is easy to disturb the setting, and essential to keep the belt taut from auxiliary pulley to inlet pulley to exhaust pulley to crankshaft puley...all the slack HAS to be on the length from the crankshaft pulley to the auxiliary pulley, where it is taken up by the tensioner. This is what sets the correct timing geometry. To be sure.....I suppose you ought to do what the book says...take the cam carriers off again....turn the engine backwards until the pistons are in the middle of their stroke...do NOT go past TDC as this could cause problems. Then refit the carriers, turn the cams so that their markings face each other... You should then have the engine valve timing set for the firing stroke on No.1 cylinder. Check the auxiliary pulley alignment....the alignment procedure is in the Service Notes, got to align it by eye, squinting from the crankshaft pulley up to the auxiliary pulley...imagining or using a real straight edge to get the marks lined up. Then check the distributor to confirm it is going to send sparks to No.1 cylinder, and refit the belt as discussed!! After that , you should be fine........but no guarantees, you have to be sure you have everything right this time!! Have fun.......

Scientists investigate that which already is; Engineers create that which has never been." - Albert Einstein

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