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XE with tappet noise part 2!


Ringmeister

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Just spoken to the guys at Raterace, Barnet who have been looking in to my tappet noise problem and a 6000 mile service on my newly acquired Vauxhall Caterham.

 

To re-cap on the problems:

 

1. From startup, lots of tappet noise for the first 2-3 miles, resolved by replacing the hydraulic followers.

2. When hot, 4000+ rpm causes tappet noise to occur which subsides after revvs return to low levels after 30 seconds.

 

Seems to be numerous things oil pressure related:

 

1. There is a certain amount of SWARF(!!!) in the oil pump and pressure relief valve. This may have come from the oil pump.

2. The oil pick-up pipe has a mounting that has been machined off and when the sump is on presses against it with a lot of pressure possibly restricting the oil flow.

3. The oil pressure relief valve has a sticking point just after the fully closed position.

 

The upshot of all this is new oil pump, new oil pick-up pipe.

 

Anyone any idea why the pick-up pipe would have a mount machined off?!

 

All in all, it probably cost £1000 with the service, smart!

 

Any thoughts/comments welcomed.

 

Ian.

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Standard Vauxhall pick up pipes have a very coarse filter built into the end. Theres no room for this in the Caterham wet sump pan so this is cut off when you fit the Vauxhall in a Caterham. Are you sure this isn't what they are talking about?

 

If you don't cut off quite enough the open end can be pressed against the bottom of the sump restricting oil pick up. If you cut off too much oil surge can be made worse. I cut mine off at the recommended depth then filed a pair of cut outs in the end of the pipe so that even if it's touching the sump there was some suction.

 

Not a good design but one of the compromises to fit such a marvellous engine in such a wonderful car. Long term fix is dry sump but that's seriously dear so most live with it.

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You need to trace the source of the swarf. This can become a big issue if it gets beyond the filter!

 

Tappets will be noisy if you use the wrong oil. USe Mobil1 Motorsport 15/50. If you still have the noise and you have new tappets you have an oil delivery problem that may well be linked to the swarf you found in the system.

 

A change to solid/converted lifters may have been a better route than replacing the std items!

 

Fat Arn

Visit the K2 RUM siteid=red>

See the Lotus Seven Club 4 Counties Area Website hereid=green>

 

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Chelspeed, what you say is true about the pick-up pipe filter. It is still attached on this engine and the mounting bracket cut off to allow the sump on (by bending the pipe)!

 

There is a circular groove on the sump where the pipe filter has been pressing against it.

 

I have been down to see the situation.

 

There is very noticable damage to the oil pump gear teeth and the pressure relief valve piston/cylinder as a result of the swarf.

 

The mechanic found no evidence of swarf in the sump and has checked the cams.

 

We are assuming the source of the swarf is the pump itself.

 

This swarf must be tough stuff (i.e. hardened steel) because of the pits it has made in the pump gear teeth.

 

We're working on the theory that the main problem with the car has been the pressure relief valve getting stuck in a partially open state causing a reduce oil pressure and hence tappet noise.

 

Fat Arnie, I currently have (had!) Syner-G in it. I tried some really thick mineral stuff as a test and it seemed to improve matters, however I removed it the following day.

 

Ian.

 

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Swarf? In sump? Suspect oil pressure?

Good God man, pull a big end shell (at least two) and inspect. That should be your first check point especially considering that the sump is off. Quite how checking the cams (very hard surfaces) is useful is beyond me.

 

Steve B

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The cams were checked to see if they could have been the source of the swarf. The big ends were thought to be ok as there was no evidence of swarf in the sump, but having said that the sump was replaced a few hundred miles ago after being broken.

 

I have spoken to the garage and the fiasco continues and costs increase.

 

1. They are going to check the big ends, they think it's a good idea and so do I.

2. They're having problems getting an orginal oil pump.

3. They are also having problems sourcing an oil pick up pipe.

 

Will I ever get this bloody car back?!

 

Will the bloody thing ever work properly without a re-mortgage on the house?

 

Getting more peed off with each day that passes.

 

i.

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If you get really stuck I have a pick up pipe from when I changed over to dry sump. I also have an oil pump which I replaced uneccesarily to solve a problem that was not caused by the pump ! (although If I were you I would choose to fit a new one).

 

Ex Chairman Roger

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ECR, thanks for the kind offer, I'll let you know!

 

Fatty, the mechanic thought it was from the pump. I think that if it were from one of the big ends then there would be some serious noise coming from it by now but the engine sounds fine when the tappet noise is not present. Also, any bearing debris would probably have a lot of difficulty getting to the oil pump because of the baffle.

 

I don't know if it's steel or alloy but the pits in the oil pump gear teeth suggest to me that the stuff was hard, also the mechanic thought they were hardened steel (apparently they were shiny).

 

The only cause of this problem that I can think of was the recent sump replacement. The previous one was cracked when it hit a cats eye. I wonder if some sump material may have got in to the pump and triggered the the problem or whilst changing the sump some debris got disturbed or introduced.

 

Ian.

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Ringmeister,

 

A magnety will help you determine what the swarf is.

 

Sounds like you need to strip the engine and clean all the oilways anyway, to be sure there is no debris left. Otherwise you are potentially driving a time bomb.

 

Any swarf at all in a bearing will casuse it to pick up and fail.

 

Fat Arn

Visit the K2 RUM siteid=red>

See the Lotus Seven Club 4 Counties Area Website hereid=green>

 

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