Timing chain tensioners

[richardtoulouse]

Thanks all,
yes, I removed the pin. However, didn't identify a difference between right and left.....

I will see that tomorow, I'll have a diner with my best friend. Because I am french, because I leave in the south west of France, we will a marvelous diner with great wine !!

My friend collect car since many year and now he have lot of Maserati from 70's. I assume that we will spend time to speak about car, engine and I am sure that he will remind with me that Italian car are marvelous.... And I agree!

Again thanks for your help, I will rework my engine tomorow, I will tell you the story and I wish that I will success!

Thanks a lot,

[Brakebuster]

Richard

enjoy your evening,

i'm sure the problem will present its self in due course,

BB

[richardtoulouse]

Hi,
I verified what I did, the right tensioner is on right.....

Take a look on the gap I have on the right:

I removed the left one and made some measurements on both. Take a look on this pitcure, the lenght of the fix distances are differents:

The distance between the contact surface (head cover) and the support of the chain that is fixe is egale of 26 mm for the original one and it is only 22.5mm for the new one:

.
It is why I have a big gap !!!

Are you award of differences references of tensioners?
The original one is SACH R39QA 965V6B209BE.
The new one came from Neville.

Thanks again for your help.

Ps: I went down to the car, removed the PMH (in french Point Mort Haut) sensor, rtemoved the plastic protection, ensure the engine is seeting at the right position. I take the opportunity by painting in black the hole to easily see it. No risk to introduce an error in the timming chain angle!

[Brakebuster]

i would say you have a stretched chain ?

and the slack is also on the unloaded side of the chain, but it seems excessive ?

i'm afraid my experience doesn't go into this sort of issue,

time for a Jaguar Tech to have a look ,

BB

[richardtoulouse]

I went to the JTIS and followed the instructions. It is where I discovered the PMH (I don't remember yhe UK name...) sensor and tool to block the engine. I saw nothing on differents tensioners

Were did you bought your tensioners?
What is the year of your car?

I will have a call to Neville and to David Marks next week (if the A350 RR engine gave me some time....) to clarify the story.

I would like to finish this S -type to start my next chantier: To unglue the read brake of my XJS, another marvelous job.

I am impatient to stop to work on my English cars and work again on the marvelous Alfa romeo engines, or on the body of my Lancia Fulvia Zagato or on the body of the Porsche 356....!!

In anthors words: The diversity is good !!!

Have a good Sunday night,
Richard

[J44EAG]

Definitely worth a call to Neville or David.

An idea from me here.

The tensioner is hydraulically operated. If you look under the old plastic tensioner face where it mates with the cylinder head, you will see an oil feed hole which forces oil into the tensioner body and there exerts force upon the lower face of the sprung loaded piston and slipper plate when the engine is running. This would expand the tensioner and exert pressure on the chain. That would take up the slack in the chain?

That is my view on the matter. Rob tells me he has never had any problems with the system, but it is still work having a talk with Neville or David.

Mike

[richardtoulouse]

Mike,
I did it.....
It is wright that the oil increase the "spring effect", the issue is the lenght of the part in oposite of the spring..... It's look too short!

My colleague from Birmigham who works on Rolls Royce engine control provided with me a marvelous advice: You have to ba a JEC member !!!!!!!

Good night,
Richard

[J44EAG]

So you are OK now, Richard?

Credit to Rob for his information in respect of oil pressure.

The piston/expansion tensioner part has a seal on the bottom and a form of pressure relief valve above the seal. Oil pressure therefore expands the tensioner when the engine is running.

I have an old plastic tensioner in my hand here. There is a wear mark on the back of the expanding slipper plate caused by it freting on the tensioner body during the time it was in my V8. The total length of the tensioner would appear to be 78mm as I see the situation.

The measurement from the tensioner base/cylinder head base to an expanded length to the top of the expanding slipper plate appears to be 26.5mm based on what I can see from the wear mark. I hope that is useful to you, Richard. You will probably see similar wear patterns on the plastic unit you have removed.

The wear mark has occurred due to lateral movement of the slipper plate and piston within the tensioner body. That sideways force then tends to stress the plastic tensioner and cracks begin to show.

Because of the 60 degree V angle of the engine, the two plane crankshaft and the design needed to phase the camshafts evenly, this results in shock or spike loading of the secondary timing chain and the tensioner. Stress reversals occur which lead to tensioner failure. The larger body of the new aluminium units has been designed to overcome the problems of the plastic units.

Thanks due to both Brake Buster and Rob for their assistance.

Mike

[robv12]

here to help old bean!!!

[richardtoulouse]

Well,
after a busy week, I went back to my complex English engine!

I fitted the left tensioner. Before I added the bolt, the pinion was free and the tensioner made his job to the chain.
Good.

I blocked the bolt (and then the pinion).
Every thing was ok.

I decided to go back to my "bad side" and to deblock the bolt to get the pinion free.
TYhe tensioner did his job!

I blocked in this position.... Every thing was ok!

I think that I had an issue with the variable timing unit that is "elastic" without oil pressure.
It went back of vew degrees making the chain not under tension.

I turned the engine few times, it's look ok.

I am waiting for my new spark plug (with the E ate teh end of teh reference), I am waiting from Neville the water expansion tank (for normal people that drive on right, not in the left side of the road !!!!!!) beforer assembly the cover rocket (I have more space).

The target? Two weeks!

Thanks all for your help.

Richard

[J44EAG]

Good to hear all has gone well, Richard.

Mike

[richardtoulouse]

Well,
I am back.
I received finally my spark plug last week (they probably came directly from ajpan due to the delay!!!!). I found some time last saturday to rebuild some parts that will allow me to start the engine .......

No bad noise, no alarm reported by the car!

I need now to re-assemble all the parts in order to make a test on the road. Target this week.

next step, to replace the oil and the cooling fluid.
I plan also to replace the breaking fluid that is the original one (2001)
The car will be new.

For the engine oil, some advice about the oil manufacturer and type?

Richard

[J44EAG]

Hello Richard.

5W-30 semi synthetic is normal.

I prefer fully synthetic as I have found my car uses less oil between oil changes and the oil stays cleaner. I am also more confident of its abilities to maintain protection under hard driving conditions. Others may not agree!

Hope that helps.

Mike

[richardtoulouse]

Hard driving?
you do not paid fuel in UK????

[J44EAG]

£1.34p for one litre now, Richard.

Perhaps less fast driving than five years ago!

Mike