transmission rattle

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mnde
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transmission rattle

Post by mnde » Mon Feb 19, 2007 4:34 pm

You know the death-rattle noise that happens if you try and pull away from low speed in 4th/5th gear. What causes that noise exactly?

What does it mean if I get that rattle noise even in 1st or 2nd gear uphill while accelerating strongly? Or even, if I have a passenger, going uphill at 60 mph in 5th.

Is it just that the 1.6 is just a real weedy engine??

But my 1.3 GSA doesn't do it!!

Cheers,

Mark.
1982 Citroen GSA Spécial Estate
1997 Renault Mégane RT 1.4e
1991 Citroen BX16 TGS Meteor - gone to Scotland

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Post by jeremy » Mon Feb 19, 2007 4:55 pm

Sounds like good old fashioned pinking!

Cause - over-advanced ignition, wrong or dirty plugs, fuel with too low an octane rating, dirty combustion chambers, hot spots caused by failing valves . . .

Generally harmless at low speed - high speed pinking will burn big holes in the pistons.

Most cars will do it on hard acceleration from low speed in top - in fact if they don't it may be the ignition timing needs looking at. If they do it too readily - then investigation is called for.

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Post by Stewart (oily!) » Mon Feb 19, 2007 5:12 pm

I agree there Jeremy, it sounds like good old fashioned pinking to me.
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mnde
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Post by mnde » Mon Feb 19, 2007 5:59 pm

Well well! That's interesting, I always thought that noise was something to do with the transmission! Re. ignition advance, I'll have to see if it still does it now because on Saturday I found that the bloomin' vacuum advance hose wasn't connected to the distributor vacuum capsule.

Plugs are only a month or so old (fitted by Chevronics), I changed the HT leads for new Bosch ones at the weekend too.

I've generally been running on 95 octane, but actually I filled up with 97 on Saturday too.

As for dirty combustion chambers and failing valves... I dunno. I know from the history that the car got all new valves and stem seals etc. etc. in around 1997 when the cambelt snapped...

I'll report back when I've driven it next!

Mark.
1982 Citroen GSA Spécial Estate
1997 Renault Mégane RT 1.4e
1991 Citroen BX16 TGS Meteor - gone to Scotland

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Post by Kitch » Mon Feb 19, 2007 6:43 pm

Sounds a bit like a rattlesnake? :lol:

I know the EW lumps are terrible for it.

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Post by jeremy » Mon Feb 19, 2007 6:46 pm

The real question of the plugs is not the age but their type - ie are they of the recommended heat range?

The vacuum pipe probably won't make any difference as there's no manifold vacuum on hard acceleration.

Remember - most cars on the road were built after 1997 - so work then is no guarantee of health now. Valves are unlikely to be the problem - a coked engine could be - in which case the problem may clear with use.

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Post by mnde » Mon Feb 19, 2007 10:41 pm

I would hope the plugs are correct as they were fitted by a Citroen specialist that I know and trust. Last ones I fitted to the car myself were of the four electrode Bosch "Plus4" type recommended for the BX...

How do you work/find out the heat range for any given plugset?

I'm going to try running on 97 or even 98 octane if I can get it. The only reason I've stuck with 95 being the price differential at the pumps... ignoring the possible economy benefits i.e. getting more mileage out of less fuel... :roll:

How do you do a timing check on a BX16?

Cheers,

Mark.
1982 Citroen GSA Spécial Estate
1997 Renault Mégane RT 1.4e
1991 Citroen BX16 TGS Meteor - gone to Scotland

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Post by AlanS » Mon Feb 19, 2007 11:17 pm

Before you get too sidetracked by assuming the problem is ping(k)ing which it may well be, have you checked the level of oil in the gearbox?
I got caught out years ago with that in a CX that had been in for service but the guy involved had drained the gearbox but not the final drive, fortunately, and been distracted. A dose of oil made all the difference to the strange noises emitting from below at some very strange times.
As regards the checking of the spark on the 1.6 engine; almost in line with the distributor towards the radiator, you'll see a bunch of pipes and wires and if you can seperate them enough to see what's below them, you'll find the clutch bellhousing and a sight hole through the top.
Connect a strobe type ignition timing light up to #1 plug lead and of course the battery, and with a decent spotlight to find the hole, jam the wires and pipes apart enough to be able to see the reading on the flywheel.
IIRC, I think they should be set at 8 BTDC and as a former owner of a 16Trs, I agree with the advice to use as high an octane rating as you can get. They do not like lower octanes and in fact will hardly run on the 91 crap we used to get, barely run on the 93 but went like a top on the 98 and the improvement in fuel economy was enough to wipe out the difference in price per litre.


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Post by mnde » Tue Feb 20, 2007 12:01 am

Hi Alan,

The clutch was changed in January, so the box has new gear oil in there and there's no indication of any leakage, so I think pinking is the culprit.

I'll see if I can get a cheap strobe tester... funnily enough I was looking at one of those Gunsons ColourTune testers: a special sparkplug with a mirror so you can see the colour of the combustion flame. Blue is good, orange is too rich.

Shell V-Power is 98/99 RON isn't it? On Saturday I filled the tank with BP Ultimate 97 RON, so I'll see how it does on that. Fuel economy in town on 95 was crap!!

Regards,

Mark.
1982 Citroen GSA Spécial Estate
1997 Renault Mégane RT 1.4e
1991 Citroen BX16 TGS Meteor - gone to Scotland

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Post by kiwi » Tue Feb 20, 2007 1:32 am

I agree with the advice to use as high an octane rating as you can get. They do not like lower octanes and in fact will hardly run on the 91 crap we used to get, barely run on the 93 but went like a top on the 98 and the improvement in fuel economy was enough to wipe out the difference in price per litre.
You know I get really frustrated when I hear this spouted on about Fuel Octanes etc. 91 octane from memory was the old 2 star leaded petrol along with 93 octane 3 star. Both were phased out before I started working for Shell back in 1991 being replaced by 95 Octance Unleaded. Four star was 97 octane repled by Lead Replacement Petrol (LRP) in 2001.

In the last 10 years there was only 3 types of petrol on the UK market
95 Unleaded, 97 4star/LRP and 98 Super Unleaded. What educated me was my first visit to New Zealand and seeing cars running on 95 Octane Leaded as it was that I was told back in England would not run. Which thinking about it explains why there are probably no BX14s in NZ.

With the exception of Britiish Built cars after 1988 the majority could run on unleaded fuels but 95 was the norm for European made cars until the Brits finally caught up.

The slight improvement in economy and power with using 98 over 95 ocatane fuel was outweighed by the extra cost of 98.

Totally agree that 91 Octane in a BX does no go! I know my wife tried it for me :oops:

BP NZ has been selling a 98 octane Unleaded in its Motorway service (Auckland only motorways) :lol: and a few places in NZ and the only fill up I used it on was when I got the car. The Fuel efficancy was extremly good but I dont know if that was to do with the long drive or Octane rating? All I do know is I had a choice of it or 91 at the time and the saving was a negative over 95 octane.

Back on Topic
Gunsons Spark testers as far as I knew is that you can use them to tune to the Fuel rating already in the tank? If your using 98 then it will indicate a tune towards it.

Would be interested to know what the price differance is at a variety of garages around the UK for 95 and 98 Unleaded? Certain terminals get a tax break which is why sometimes the differance in 98 prices can vary more than 95.

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Post by mnde » Tue Feb 20, 2007 12:40 pm

kiwi wrote: Would be interested to know what the price differance is at a variety of garages around the UK for 95 and 98 Unleaded? Certain terminals get a tax break which is why sometimes the differance in 98 prices can vary more than 95.
http://www.petrolprices.com

Regards,

Mark.
1982 Citroen GSA Spécial Estate
1997 Renault Mégane RT 1.4e
1991 Citroen BX16 TGS Meteor - gone to Scotland

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Post by kiwi » Tue Feb 20, 2007 7:12 pm

Bugger forgot about that site :oops:

Probably should post this elsewhere but does anyone know what percentage of Ethenol you can have mixed in your petrol without causing the BX any problems?

Yep Kiwi Goverment is going to add ethanol to our petrol and already the doom and gloom predictions of leaky fuel hoses caused by the mix have started. Same thing happenned in 1996 when Lead was removed from 95 octane and people with old cars blamed the fuel for melting OLD fuel lines.

Although the Avgas mixture of 30% I had to use on the BX with the 91 octane mess up, Was a nice mixture 8) Trouble is Avgas is a little expensive :wink:

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Post by adamskibx » Tue Feb 20, 2007 10:35 pm

I know it doesnt exactly add up, but when my vacume pipe came off on the GT, it started pinking in certain situations. I cant remember when exactly, but when I found the pipe had come off, and put it back on, all was fine again. It might be OK now youve put it back on.

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Post by AlanS » Wed Feb 21, 2007 2:37 am

We've been running ours on 10% for the last couple of years with no problems.
I run the 95 in the Xantia the TZi and Tri & 98 in the 16V.

It has been suggested that based on the last time they gave Ethanol a go over here and its use was scrapped due to the scarey stories that abounded eminating from one particular oil company with a very dubious reputation, that once Oil companies started investing in cane farms there might be a sudden shift in attitudes towards ethanol.
On a trip through the northern tablelands of New South Wales last year on a couple of occasions, I drove for literally over an hour through acres of sorghum plants, one of the plants being used for ethanol production and in some cases, small signs with oil company logos were visible but not readable on corner posts, so that may have already started. Problem now of course is that with this historic drought we're in, they'll use that as an excuse to jack up prices all the more.
My argument that ethanol can't be all that bad for a cars system is the fact that not only did we use it in racing fuels years ago, but if anyone ever buys a fuel system cleaner, ethanol in one form or another is usually the main ingredient, which maked their arguments somewhat hypocritical.
For the record, on my old 16Trs, the difference between using LRP and Premium unleaded was just over 10% improvement based on several tankful to tankful trials.


Alan S




kiwi wrote:
I agree with the advice to use as high an octane rating as you can get. They do not like lower octanes and in fact will hardly run on the 91 crap we used to get, barely run on the 93 but went like a top on the 98 and the improvement in fuel economy was enough to wipe out the difference in price per litre.
You know I get really frustrated when I hear this spouted on about Fuel Octanes etc. 91 octane from memory was the old 2 star leaded petrol along with 93 octane 3 star. Both were phased out before I started working for Shell back in 1991 being replaced by 95 Octance Unleaded. Four star was 97 octane repled by Lead Replacement Petrol (LRP) in 2001.

In the last 10 years there was only 3 types of petrol on the UK market
95 Unleaded, 97 4star/LRP and 98 Super Unleaded. What educated me was my first visit to New Zealand and seeing cars running on 95 Octane Leaded as it was that I was told back in England would not run. Which thinking about it explains why there are probably no BX14s in NZ.

With the exception of Britiish Built cars after 1988 the majority could run on unleaded fuels but 95 was the norm for European made cars until the Brits finally caught up.

The slight improvement in economy and power with using 98 over 95 ocatane fuel was outweighed by the extra cost of 98.

Totally agree that 91 Octane in a BX does no go! I know my wife tried it for me :oops:

BP NZ has been selling a 98 octane Unleaded in its Motorway service (Auckland only motorways) :lol: and a few places in NZ and the only fill up I used it on was when I got the car. The Fuel efficancy was extremly good but I dont know if that was to do with the long drive or Octane rating? All I do know is I had a choice of it or 91 at the time and the saving was a negative over 95 octane.

Back on Topic
Gunsons Spark testers as far as I knew is that you can use them to tune to the Fuel rating already in the tank? If your using 98 then it will indicate a tune towards it.

Would be interested to know what the price differance is at a variety of garages around the UK for 95 and 98 Unleaded? Certain terminals get a tax break which is why sometimes the differance in 98 prices can vary more than 95.
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mnde
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Post by mnde » Wed Feb 21, 2007 11:55 am

adamskibx wrote:I know it doesnt exactly add up, but when my vacume pipe came off on the GT, it started pinking in certain situations. I cant remember when exactly, but when I found the pipe had come off, and put it back on, all was fine again. It might be OK now youve put it back on.
Yes, I thought that although Jeremy said there's no manifold vacuum on hard acceleration, having the hose disconnected is nevertheless a source of a vacuum leak, sucking in extra air.

Well it didn't do it this morning like it used to in 2nd gear up the steep hill to my girlfriend's place. Will have to wait and see. It can only help that I've changed the grade of fuel at the same time!

Cheers,

Mark.
1982 Citroen GSA Spécial Estate
1997 Renault Mégane RT 1.4e
1991 Citroen BX16 TGS Meteor - gone to Scotland