efreeti's broken tourer - suggestions welcome!

efreeti · 10th January 2009, 19:37

Well I took the cam cover off the auto tourer today to try and find the source of the knocking.

It started getting dark by the time we actually got the cover off so only managed to get a look at the top of the cams so far.

You will see the photos below show quite a lot of damage to 2 of the cam lobes on the exhaust cam. As far as I can see none of the other lobes show any signs of damage but won't be able to turn the engine over until the daylight returns.

It looks as though there is also damage (squashing?) to the relevant edges of the tops of the rocker arms which the lobes run in to.

Not obvious from the picture but the lobes are the first two from the left hand side of the head. We always thought the noise seemed to be coming from around no 1 piston so it all seems to makes sense.

We will doubtless know more tomorrow but in the meanwhile if anybody has any suggestions, guesses, or even wagers on the root of the problem, I am all ears :-)

Close Up:

efreeti · 10th January 2009, 19:38

Oops, they seem a bit big. Will reduce the size once I get the kids to bed!

T-Cut · 10th January 2009, 19:49

I don't see anything particularly unusual. The working surfaces appear OK to me. (??)

pondweed · 10th January 2009, 19:59

there looks to be lots of swarf on the edges....

Chorkie-Dad · 10th January 2009, 20:00

The cam lobe does not contact the rocker on its full width,contact area can been seen clearly in the image, outer edge is irrelevant to your problem, check valve clearance almost in the position of the lobe at present.
Are all other exhaust lobes similar(high mileage)if not could be exhaust valve starting to recess into valve seat

efreeti · 10th January 2009, 20:47

I need to have a look in the light really but from what I could see the other lobes seemed more like the outer edges of those pictured. I take your point that it doesn't seem to be in the contact area.

Just wondering about the marks on the rocker arm walls. Impossible to get a picture at the moment.

I am trying to stay optimistic :lol:

moonstoneboy · 11th January 2009, 06:23

I would be quite concerned at this - where has the metal from the edges gone - and more importantly, what are they doing

Paul

kaiser · 11th January 2009, 09:47

From what can be seen here, it just looks as if the cams are finished rough from the factory, they have been ground on the surface of the lobes, and that is all you really need.
You will have to measure to see if the shape and the lift is
OK.

efreeti · 11th January 2009, 10:28

On closer inspection in the daylight it does seem as though there are degrees of rough edge on all the lobes. One side seems spot on and the other rough.

Some of the stuff that looks like swarf on the photo is kitchen roll thread which I used to give the area a bit of a wipe. I am going to have a run over with a magnet but I don't think there is a huge amount.

Going to check the oil filter first and then continue investigating the top end. Just doesn't sound like an engine knock, it sounds to be coming from the top left and is a nicely timed loud tap that speeds up smoothly with revs. Engine runs really really smooth as well.

Jules · 11th January 2009, 10:44

Hi Jim
Try & use "Kimwipe" large blue roll (available from motor factors) instead of Kitchen roll. It doesn't shed fibres like kitchen roll!!

Good enough for RAF aircraft, good enough for cars

What oil brand & change intervals have you been using?
The cam edges just look like the rough casting to me and were probably installed like that.
Good luck with your investigations.

10th January 2009, 19:37	#1
efreeti Gets stuck in ZT-T CDT 130+ (04) & 75 Tourer CDT Auto (52) & a 1998 MGF (with HGF!) Join Date: Mar 2007 Location: Halifax Posts: 903 Thanks: 0 Thanked 1 Time in 1 Post	efreeti's broken tourer - suggestions welcome! Well I took the cam cover off the auto tourer today to try and find the source of the knocking. It started getting dark by the time we actually got the cover off so only managed to get a look at the top of the cams so far. You will see the photos below show quite a lot of damage to 2 of the cam lobes on the exhaust cam. As far as I can see none of the other lobes show any signs of damage but won't be able to turn the engine over until the daylight returns. It looks as though there is also damage (squashing?) to the relevant edges of the tops of the rocker arms which the lobes run in to. Not obvious from the picture but the lobes are the first two from the left hand side of the head. We always thought the noise seemed to be coming from around no 1 piston so it all seems to makes sense. We will doubtless know more tomorrow but in the meanwhile if anybody has any suggestions, guesses, or even wagers on the root of the problem, I am all ears :-) Close Up: __________________ Jim Replace in tank fuel pump with Peugeot alternative Dismantle and re-fit interior and seats Retrofit electric memory seats without the loom All followed at your own risk! Available to borrow: I have a home made (tried and tested) Cam Locking tool for M47 should anyone need it.

10th January 2009, 19:38	#2
efreeti Gets stuck in ZT-T CDT 130+ (04) & 75 Tourer CDT Auto (52) & a 1998 MGF (with HGF!) Join Date: Mar 2007 Location: Halifax Posts: 903 Thanks: 0 Thanked 1 Time in 1 Post	Oops, they seem a bit big. Will reduce the size once I get the kids to bed! __________________ Jim Replace in tank fuel pump with Peugeot alternative Dismantle and re-fit interior and seats Retrofit electric memory seats without the loom All followed at your own risk! Available to borrow: I have a home made (tried and tested) Cam Locking tool for M47 should anyone need it.

10th January 2009, 20:00	#5
Chorkie-Dad Newbie Rover 75 CDT Join Date: Dec 2008 Location: Scotland Posts: 9 Thanks: 0 Thanked 0 Times in 0 Posts	Cam Lobe The cam lobe does not contact the rocker on its full width,contact area can been seen clearly in the image, outer edge is irrelevant to your problem, check valve clearance almost in the position of the lobe at present. Are all other exhaust lobes similar(high mileage)if not could be exhaust valve starting to recess into valve seat

10th January 2009, 20:47	#6
efreeti Gets stuck in ZT-T CDT 130+ (04) & 75 Tourer CDT Auto (52) & a 1998 MGF (with HGF!) Join Date: Mar 2007 Location: Halifax Posts: 903 Thanks: 0 Thanked 1 Time in 1 Post	I need to have a look in the light really but from what I could see the other lobes seemed more like the outer edges of those pictured. I take your point that it doesn't seem to be in the contact area. Just wondering about the marks on the rocker arm walls. Impossible to get a picture at the moment. I am trying to stay optimistic :lol: __________________ Jim Replace in tank fuel pump with Peugeot alternative Dismantle and re-fit interior and seats Retrofit electric memory seats without the loom All followed at your own risk! Available to borrow: I have a home made (tried and tested) Cam Locking tool for M47 should anyone need it.

11th January 2009, 10:28	#9
efreeti Gets stuck in ZT-T CDT 130+ (04) & 75 Tourer CDT Auto (52) & a 1998 MGF (with HGF!) Join Date: Mar 2007 Location: Halifax Posts: 903 Thanks: 0 Thanked 1 Time in 1 Post	On closer inspection in the daylight it does seem as though there are degrees of rough edge on all the lobes. One side seems spot on and the other rough. Some of the stuff that looks like swarf on the photo is kitchen roll thread which I used to give the area a bit of a wipe. I am going to have a run over with a magnet but I don't think there is a huge amount. Going to check the oil filter first and then continue investigating the top end. Just doesn't sound like an engine knock, it sounds to be coming from the top left and is a nicely timed loud tap that speeds up smoothly with revs. Engine runs really really smooth as well. __________________ Jim Replace in tank fuel pump with Peugeot alternative Dismantle and re-fit interior and seats Retrofit electric memory seats without the loom All followed at your own risk! Available to borrow: I have a home made (tried and tested) Cam Locking tool for M47 should anyone need it. Last edited by efreeti; 11th January 2009 at 10:30..

10th January 2009, 19:49	#3
T-Cut This is my second home Rover75 and Mreg Corsa. Join Date: Nov 2006 Location: Sumweer onat mote o'dust (Sagin) Posts: 21,754 Thanks: 341 Thanked 3,660 Times in 2,924 Posts	I don't see anything particularly unusual. The working surfaces appear OK to me. (??)

10th January 2009, 19:59	#4
pondweed This is my second home Waiter, Waiter! I seem to have a Roomster in my drive... Join Date: Nov 2006 Location: Sussex Posts: 3,268 Thanks: 0 Thanked 1 Time in 1 Post	there looks to be lots of swarf on the edges....

11th January 2009, 06:23	#7
moonstoneboy Posted a thing or two Rover 75 Connoisseur SE CDT Tourer - naturally in Moonstone Green Join Date: Oct 2007 Location: Surrey - near Gatwick Airport Posts: 1,316 Thanks: 0 Thanked 3 Times in 3 Posts	I would be quite concerned at this - where has the metal from the edges gone - and more importantly, what are they doing Paul

11th January 2009, 09:47	#8
kaiser This is my second home 75 Tourer 2.5 Auto, 1.8T, 75V8ZT Join Date: Jun 2007 Location: Johannesburg ZA Posts: 6,200 Thanks: 1 Thanked 859 Times in 613 Posts	From what can be seen here, it just looks as if the cams are finished rough from the factory, they have been ground on the surface of the lobes, and that is all you really need. You will have to measure to see if the shape and the lift is OK.

11th January 2009, 10:44	#10
Jules This is my second home ZT 260 SE Twilight and 10 other 75 ZT's :O Join Date: Jan 2007 Location: Conwy NORTH WALES Posts: 11,094 Thanks: 512 Thanked 1,116 Times in 763 Posts	Hi Jim Try & use "Kimwipe" large blue roll (available from motor factors) instead of Kitchen roll. It doesn't shed fibres like kitchen roll!! Good enough for RAF aircraft, good enough for cars What oil brand & change intervals have you been using? The cam edges just look like the rough casting to me and were probably installed like that. Good luck with your investigations. __________________ [SIGPIC][/SIGPIC] Newbies do now!! 1. Plenum drains..all 3 or 4 year dependent 2. Cooling fan..All speeds functioning 3. Bonnet cable divider block Last edited by Jules; 11th January 2009 at 10:47..