Duff tensioner (75 Diesel)

zaph · 4th January 2020, 15:41

I have been trying to fix the alternator and the noise from the belt area. (diesel)

I have fitted a new alternator, crank pulley, idler pulley and belt. Still have large amount of flutter between the crank and the alternator. With a brand new alternator only giving between 13.2-6 volts, sometimes dropping as low as 12.9v.

The tensioner pulley is bouncing when the engine is running but I don't how much movement there should be?

How do you actually change the tensioner, the Heynes manual is useless as normal and just tells me to take it off. With no indication as to how you're suppose to do this.

zaph · 4th January 2020, 20:49

OK I have just compared it to a good 75 Diesel and the movement of my belt between the alternator and the crank pulley is excessive.

I have also had another look at the Heynes manual and realised that the L-shaped bracket is not the tensioner, that is buried in the engine and looks a nightmare to replace. They are talking about removing the cylinder head. Frankly if it involves all that the car might be beyond economic repair.

However I am beginning to suspect the crank pulley due to where the flutter is. It is a new unit but I wonder if it is out of spec?

Mike Noc · 5th January 2020, 09:20

The tensioner isn't that much of a job to replace - only two bolts but you need to unbolt the engine mount and drop the engine down to remove the arm.

Was the replacement crank pulley a genuine Corteco?

rovertone · 5th January 2020, 11:20

I found that the 'flutter, on my belt was due to a failing crank pulley having changed the tensioner first to no avail, albeit my pulley was well used and not new. as far as the tensioner is concerned, as Mike has posted it is not too bad a job the biggest problem I had was trying to get the small nut and washer on the end of the L shaped bracket. Having fingers like bananas doesn't help.

Have you tried looking at the crank pulley with the engine running ( move wing liner away) put a spot of paint on the face of the pulley flange and you will see if there is any uneven running concentrically (if that's the right terminology). On mine there was already a mark of the pulley and you could see the pulley 'bouncing'.
Good luck

zaph · 5th January 2020, 17:08

Quote:

Originally Posted by Mike Noc

The tensioner isn't that much of a job to replace - only two bolts but you need to unbolt the engine mount and drop the engine down to remove the arm.

Was the replacement crank pulley a genuine Corteco?

That is good news, the Heynes manual is telling me to remove the cylinder head.

The crank pulley is the discount rover spares OEM one.

zaph · 5th January 2020, 17:13

Quote:

Originally Posted by rovertone

I found that the 'flutter, on my belt was due to a failing crank pulley having changed the tensioner first to no avail, albeit my pulley was well used and not new. as far as the tensioner is concerned, as Mike has posted it is not too bad a job the biggest problem I had was trying to get the small nut and washer on the end of the L shaped bracket. Having fingers like bananas doesn't help.

Have you tried looking at the crank pulley with the engine running ( move wing liner away) put a spot of paint on the face of the pulley flange and you will see if there is any uneven running concentrically (if that's the right terminology). On mine there was already a mark of the pulley and you could see the pulley 'bouncing'.
Good luck

I have watched it running and it seems to be running pretty true. However I don't know, to honest I am getting pretty fed up with this, it is a loosey design.

The access is terrible and I have run a couple of cars up to 200K miles, without having the auxiliary belts fail. Of course those cars had good old solid crank pulleys and bullet proof alternators. To be fair I had to change the cam belts but even that was easier on past cars that working on this belt this close to the wing.

rovertone · 5th January 2020, 21:45

In my case the new tensioner improved the belt bounce only slightly so like you unsure what the problem was I motored on. The pulley finally failed 15000 miles later.
Again on mine, when the revs were raised above idle the belt 'bounce' smoothed out which is why I decided to risk leaving it.

Just a note on strength of the aux drive belt I had an alternator fail, the pulley bearings broke up and seized the shaft solid and the engine stalled when it was doing about 1500rpm. I couldn't believe that it hadn't snapped the belt or slipped.

clf · 5th January 2020, 22:15

Quote:

Originally Posted by zaph

I have watched it running and it seems to be running pretty true. However I don't know, to honest I am getting pretty fed up with this, it is a loosey design.

The access is terrible and I have run a couple of cars up to 200K miles, without having the auxiliary belts fail. Of course those cars had good old solid crank pulleys and bullet proof alternators. To be fair I had to change the cam belts but even that was easier on past cars that working on this belt this close to the wing.

spray bottle with water, and spray the pulley whilst it is running. If it quietens down, and then gets noisy again, the pulley is on the way out.

VIDEO

zaph · 6th January 2020, 05:42

Quote:

Originally Posted by clf

spray bottle with water, and spray the pulley whilst it is running. If it quietens down, and then gets noisy again, the pulley is on the way out.

VIDEO

The pulley is virtually new, so it shouldn't have failed so soon.

Mike Noc · 6th January 2020, 08:30

True but the compliance of the rubber may not be correct, and so the pulley may not be dampening out the drive from the crankshaft.

Personally I would only fit a genuine Corteco Pulley.

Does the engine idle sound nice and even? maybe an injector fault could also cause a bit of belt flutter?

4th January 2020, 15:41	#1
zaph Avid contributor Rover 75 Join Date: May 2015 Location: Leeds Posts: 135 Thanks: 0 Thanked 17 Times in 11 Posts	Duff tensioner (75 Diesel) I have been trying to fix the alternator and the noise from the belt area. (diesel) I have fitted a new alternator, crank pulley, idler pulley and belt. Still have large amount of flutter between the crank and the alternator. With a brand new alternator only giving between 13.2-6 volts, sometimes dropping as low as 12.9v. The tensioner pulley is bouncing when the engine is running but I don't how much movement there should be? How do you actually change the tensioner, the Heynes manual is useless as normal and just tells me to take it off. With no indication as to how you're suppose to do this. Last edited by zaph; 4th January 2020 at 15:50..

5th January 2020, 11:20	#4
rovertone Gets stuck in Rover 75 Conne SE Auto CDTi Join Date: Nov 2012 Location: Redditch Posts: 669 Thanks: 185 Thanked 135 Times in 109 Posts	I found that the 'flutter, on my belt was due to a failing crank pulley having changed the tensioner first to no avail, albeit my pulley was well used and not new. as far as the tensioner is concerned, as Mike has posted it is not too bad a job the biggest problem I had was trying to get the small nut and washer on the end of the L shaped bracket. Having fingers like bananas doesn't help. Have you tried looking at the crank pulley with the engine running ( move wing liner away) put a spot of paint on the face of the pulley flange and you will see if there is any uneven running concentrically (if that's the right terminology). On mine there was already a mark of the pulley and you could see the pulley 'bouncing'. Good luck __________________ 2003 Mk 1 Connie SE CDTi Auto Monogram Mirage 2/Sandstone Leather 511th CDTi out of 4744 produced 9th in Mirage 2 out of 17 produced Also 2004 Rover 25 SXi CVT, 1999 Megane Cabriolet and still missing my 800 Fastback.

5th January 2020, 21:45	#7
rovertone Gets stuck in Rover 75 Conne SE Auto CDTi Join Date: Nov 2012 Location: Redditch Posts: 669 Thanks: 185 Thanked 135 Times in 109 Posts	In my case the new tensioner improved the belt bounce only slightly so like you unsure what the problem was I motored on. The pulley finally failed 15000 miles later. Again on mine, when the revs were raised above idle the belt 'bounce' smoothed out which is why I decided to risk leaving it. Just a note on strength of the aux drive belt I had an alternator fail, the pulley bearings broke up and seized the shaft solid and the engine stalled when it was doing about 1500rpm. I couldn't believe that it hadn't snapped the belt or slipped. __________________ 2003 Mk 1 Connie SE CDTi Auto Monogram Mirage 2/Sandstone Leather 511th CDTi out of 4744 produced 9th in Mirage 2 out of 17 produced Also 2004 Rover 25 SXi CVT, 1999 Megane Cabriolet and still missing my 800 Fastback.

4th January 2020, 20:49	#2
zaph Avid contributor Rover 75 Join Date: May 2015 Location: Leeds Posts: 135 Thanks: 0 Thanked 17 Times in 11 Posts	OK I have just compared it to a good 75 Diesel and the movement of my belt between the alternator and the crank pulley is excessive. I have also had another look at the Heynes manual and realised that the L-shaped bracket is not the tensioner, that is buried in the engine and looks a nightmare to replace. They are talking about removing the cylinder head. Frankly if it involves all that the car might be beyond economic repair. However I am beginning to suspect the crank pulley due to where the flutter is. It is a new unit but I wonder if it is out of spec?

5th January 2020, 09:20	#3
Mike Noc This is my second home Rover 75 CDT Manual Connoisseur SE, Rover 75 CDT Automatic Connoisseur SE & a Freelander Td4. Join Date: Jul 2009 Location: Hampshire Posts: 11,548 Thanks: 3,470 Thanked 3,119 Times in 2,247 Posts	The tensioner isn't that much of a job to replace - only two bolts but you need to unbolt the engine mount and drop the engine down to remove the arm. Was the replacement crank pulley a genuine Corteco?

6th January 2020, 08:30	#10
Mike Noc This is my second home Rover 75 CDT Manual Connoisseur SE, Rover 75 CDT Automatic Connoisseur SE & a Freelander Td4. Join Date: Jul 2009 Location: Hampshire Posts: 11,548 Thanks: 3,470 Thanked 3,119 Times in 2,247 Posts	True but the compliance of the rubber may not be correct, and so the pulley may not be dampening out the drive from the crankshaft. Personally I would only fit a genuine Corteco Pulley. Does the engine idle sound nice and even? maybe an injector fault could also cause a bit of belt flutter?