Camshaft Tensioner

acrowot · Post by **acrowot** » 30 May 2006, 22:09

I have just accuired a 1998 facelift Xantia TD 1905cc DHX, this car has a blown Headgasket. The car had a similar problem a few months ago and the radiator and headgasket were replaced, allegedly by a garage somewere in the Birmingham area. There were no gaskets fitted to the exhaust or inlet manifold, just copious amounts of red Hermitite, do these engines not require gaskets in this area, in fact the only gaskets on the head are the headgasket and rocker cover gasket. There were quite a few jubilee clips missing and some of the ones not missing were not tightened including the Intercooler outlet. Anyway the bottom hose detached itself from the radiator it lost all the water and the head gasket was damaged again, I bought it at this point, very cheap. Apart from there only being four of the 6 exhaust manifold bolts in place and 3 inlet manifold bolts missing, also missing is the Camshaft Tensioner spring and plunger, does anyone know what this tensioner does because once the belt is tensioned ( it does seem that you do not need the tensioner to do this ) and the 2 bolts on the tensioner are tightened then the tensioner plays no further part in the tensioning, if all this is true what is the purpose of this tensioner. I would like to add that I will be replacing the tensioner but it does seem to be not required, I must be missing something.Do you think the head would be reusable with a skim and pressure test, I do beleive this was not done on the first failure.

Dave Burns · Post by **Dave Burns** » 30 May 2006, 22:47

The tensioner does exactly that, it tensions the belt at time of fitting, it can't do this if there is no spring or plunger present, once correctly tensioned the roller assembly is locked in place via the two bolts, from then on the spring plays no further part, but without it you will be guessing at what should be the correct tension for the timing belt.

There should be gaskets on both manifolds.

If this head has had two roastings I personaly would not risk wasting money on it.

Dave

acrowot · Post by **acrowot** » 30 May 2006, 22:54

Thanks for your reply Dave, your comments were my thoughts also, the only thing I do not uderstand is why is that there is a tool for setting this tension if the tesioner does this for you, also people suggest that if you have no access to this tool then mid point longest run able to twist belt through 90 degrees. On previous cambelt changes I have let the tesioner tension the belt and accepted that this is correct, but why the tool?.

Post by **Peter.N.** » 30 May 2006, 23:20

The tool is not for setting the tensioner but for locking it in the non tensioned position to allow you to remove the cam belt. You can tension the belt without the spring and plunger by levering against the pully and then locking the bolts but this isn't very accurate. The spring sets the correct tension when the bolt is released. The correct tool is an allen key.

acrowot · Post by **acrowot** » 30 May 2006, 23:26

I think we are talking about 2 different tools here, the tool you describe is 3/8 square and is used for releasing the tension on the belt when removing it, the tool I am talking about is I believe some sort of electronic device allegedly used by Main Agents for setting the tension.

Kowalski · Post by **Kowalski** » 30 May 2006, 23:40

acrowot wrote:I think we are talking about 2 different tools here, the tool you describe is 3/8 square and is used for releasing the tension on the belt when removing it, the tool I am talking about is I believe some sort of electronic device allegedly used by Main Agents for setting the tension.

Have you actually seen the mechanics at a main dealer use "the tool"?

The fact is, if the dealer has the tool, I doubt very much that they'll use it. Perhaps this is a little cynical of me to say but, the tool is there so that later on if the belt breaks prematurely they can claim they used the tool, so that means it isn't their fault any more in their minds.

acrowot · Post by **acrowot** » 30 May 2006, 23:54

No I have not seen the tool, but this seems to be getting away from the point that I am trying to make, it would seem that this tool does exist and as I say some people say that if this tool is not available ( which I am sure it is not to most people because of it's cost ) then an alternative method of checking the tension would be to grip the belt between thumb and forefinger then you should be able to twist the belt through 90 degrees. The point that I am trying to make is why are these methods necessary if the tensioner applies the correct tension when the bolt that is securing it is released allowing the tensioner to apply the correct tension. I am not saying that the tensioner does not do this of it's own accord. I am just wondering how important is this tensioner if one of the other two methods can be used. The first reply that I received from Dave was the informative reply that I was looking for, I would just have liked his comments on the point that I explained above.

Post by **Peter.N.** » 31 May 2006, 09:31

I'm confused

, anyway, I shall probably be castigated for saying this but I dont think the setting is all that critical. If you check the tension 10-20k after fitting the belt, it can be quite sloppy and will go on running like this until it is next changed, without slipping or falling off. As long as it is reasonably tight when fitted, the '90 degree twist' is a reasonable guide. Very few people check the tension of the belt once fitted and when changed again I have been amazed how it has continued to operate in its slack state.

acrowot · Post by **acrowot** » 31 May 2006, 10:36

Thanks for your reply Peter, as I have said all I was wondering is just how important is this tensioner, I cannot see the manufacturer fitting it if it is not required, but it seems it is possible to adjust the belt by other means. I was very surpised to see that on my engine it had been removed yet the belt did seem to be OK.

Dave Burns · Post by **Dave Burns** » 03 Jun 2006, 09:32

The tool for setting belt tension exists because not all engines have a spring loaded adjuster which applies the correct tension.
Because this engine does have such an adjuster there probably isn't any data available for setting its belt tension using such a tool anyway.
If you think that such a critical operation of the engine can be gauged by simply twisting a belt then go right ahead its your engine, if you don't then get the spring and plunger, all the guesswork then goes out the window and you fit your belt safe in the knowledge that its been tensioned correctly.

Dave

acrowot · Post by **acrowot** » 03 Jun 2006, 09:58

Thanks for your reply Dave, if you read my OP you will see that I do intend to replace the tensioner and spring, I was just wondering what the purpose of the tensioner was when there did seem to be other methods of tensioning this belt. When my engine is rebuilt ( if ever, I may replace it ) it will be complete as origional with all the bits on it. I do respect your opinion and and no way am I trying to suggest that you are in any way incorrect, I am just searching for answers.

reblack68 · Post by **reblack68** » 03 Jun 2006, 10:41

I wouldn't bother doing any work on that engine, I would never trust it after seeing the amount of cowboy work done on it. By the time you have bought all the missing/ broken bits you would have spent enough to buy a whole engine or a running scrapper.

I would also be tempted to report the garage to Trading Standards, they shouldn't be in business.

acrowot · Post by **acrowot** » 03 Jun 2006, 12:16

Hi Redblack, thanks for your reply, I am trying to decide what to do, I do have a second engine that is out of a Peugeot 406 with 220,000 miles on ithe clock. My Grandson obtained this engine from his friend who works in a scrap yard, they are very good friends and my Grandson was assured that the engine ran fine and I paid £50.00 for it, but I have not heard it running, this scrap yard would normally charge £250.00 for this type of engine. The little engine number plate on the block is missing so I do not know it's type, my engine is a DHX, there are some minor differences mainly in the exhaust manifold area. My main problem with the fitting of this "new" engine is that I am not sure how the immobiliser works on this type of engine, it is a Mk2 facelift with a chip in the key not a keypad. Both these engines appear to be the later type, the older Xantias had the immobiliser on the pump, is it still the same with the later ones, so a pump change would solve my problem, or is it immobilised perhaps with the ECU. I do not know the garage that did thev origional repair, I did not own it then, I was told by the seller that a garage had done the job. It was of such a poor standard that I find it hard to believe, I do not know what garage standards are like as I do my own sevicing and repairs. I hasten to add I bought the car after the second failure with the full knowledge of the faults. The car otherwise is in very good condition and the price I paid for it was very cheap.