K Simmons

OK, I replaced a burned or burnt exhaust valve on the front head. While I was in there I decided to find source of my clicking(VTCs i thought). I did rebuild both VTC before I found that the chain tensioner on the rear haed was basically destroyed. I replaced it and all was well for about 50 miles. After that I started hearing a different sound that sound like the timing chain hitting the valve cover. I opened it up again and found that the chain that is oposite the tensioner had fallen off(I don't remember loosening those bolts). I bought a new guide because this one was beat up a bit. After installing it and putting everything together, the tensioner will fully extend while the exhaust valves are opening. Just after the lobe reaches the its highest point, the valve spring actually turns the cam which pulls all the slack out of the chain and the tensioner is completely bottoms. I think this is the noise I heard. The tensioner on the front head barely moves as the engine is turned over.

I had done a compression test before installing the new guide and had one cylinder on the rear head as low as 160PSI and a high one on the front head at 210PSI. Now that I have replaced the guide, which required the removal of one of the cam sprockets, the rear cylinders are all over 230PSI. I wonder if the valve timing was off before and is now corrected. The front cylinders range from 180-210.

The question is: Does the cam chain tensioner require oil pressure to work properly? I hope that when the engine is running the oil pressure will push the tensioner out and keep the slack on the correct side.

Any help will be greatly appreciated.

Czar

Yes, the cam chain tensioner requires oil pressure to work even though there maybe a spring in there. Due to the valve spring's pressure turning the cam unevenly, there is no way to diagnose correctly the chain looseness condition while just turning it over manually. I am not sure if you also replaced the front chain tensioner at the same time, but the cams will resist turning to a certain point(causing the slack on the front), and then as the cam reaches the top of the cam lobe, it will suddenly turn, pulling the slack out of the front fo the chain and dumps it either between the two cam sprockets or on the other side of the sprockets. So once the engine is running, the chain is moving fast enough that the slack will stay on the correct side and the oil pressure wil push the tensioner out to take up that slack. I don't know how many miles you have on your engine, but if you say that one of your chains stays relatively tight throughout the movement of the engine and the other one has a lot more slack, you may have a worn timing chain and it has stretched a bit causing extra slack that hits your tim ng chain cover. Maybe this can help. Good luck!!

bigjay

upper timming chain guides warped or misalined, also if you install the tensioners on the wrong sides (right on the left, or vise versa youll have trouble because there diffrent,just a possability but you probally know this),lower timming chain guides, warped or damaged idler sprokets or missing teeth. just a brain storm of somethings it could be but im sure youve already check these things, also czar might have been onto something with the faulty chain, check for anyexcessive wear with the roller links, and any small cracks

K Simmons

I considered the posibility of the front and rear tensiners being different. But when I bought guide for the rear head I asked about the part numbers, the parts guy said they had the same number. Are you sure that they are different? When I bought this tensioner, it was for the front head. After buying it I saw that the rear one was broken so I put it on the back(they looked the same to me). If it make any difference at all, I am getting oil to the rear chain(I think this comes thru the tensioner).

I am thinking I may go and buy a rear tensioner if they are different.

thanks for your help,,both of you

later,

Jeff92se

iTrader: (82)

Wow! Some knowledgable guys here! Glad to see the VE info going.

Hey just one note to add. K. Simmons, this is gonna sound dumb but did you remember to "unhook" the tensioner "latch" when you installed it? There is a hookd to hold the tension when you remove and install it. And also did you remember to run a small wire though the feed hole to make sure it was not clogged?

bigjay

there are two diffrent type's, you dont want to install the left one onto the right cylender head, this will create problems

K Simmons

Ok then, I guess I will be replacing the chain tensioner on the rear or left head tomorrow. I will let you know what happens.

K Simmons

I will be replacing the spark plugs on the car tonight and will know if I was successful tomorrow. I replaced the rear tensioner and it did seem "better" but still moved more than Iwould like. I am going to hope that the oil pressure will stop this.

I now believe that the noise I was hearing and the loss of power that I noticed were the results of different problems. I am sure that the noise was coming from the tensioner, but I also found a loose fuel line(pressure side). I need to fire myself as a mechanic!!!! The area arround the connection from the rubber line to the fuel rail was covered with white powder, I am guessing that this is a result of gas being sprayed on a hot surface.

I will know more tomorrow.

Later,