What is causing noise from the CAS?

[juneaubehr]

There is an awful metallic sound coming from the CAS. I have not removed the cover to investigate what is causing the noise, because I am not the owner, I am just looking at purchasing the car. I would like some of your inside knowledge if anyone has experienced this problem before. Am I looking at replacing the CAS, or rebuilding the head? The car runs fine, accelerates normally, it's just making a awful noise. I have looked for a replacement complete CAS unit with no luck. I've tried Isuzu and Dave Bean, and Rockauto. Any help that someone can provide would be appreciated. Thanks!

[Brit-Car-Nut]

A NEW Cas will be almost impossible to find. Used ones pop up on eBay sometimes. There are a lot of moving parts inside, so it could be the HES has moved and hitting the wheel or the wheel is bent and hitting the HES or something has gotten inside and chewing it up.

Which one are you looking at? (What part of the US and is it listed anywhere?)

[Andy_J]

Could be the bearing that has gone.

The bearing can be replaced, but it is not a straight forward job as you would need to source the bearing

[juneaubehr]

Thanks for the info. I found the car in Wahington State.106k Miles. red, needs seats redone, CAS, and outboard CV joint. Is this a decent deal for $5k?

[steve matthews]

Pictures and are you handy with tools:?:

Steve

[juneaubehr]

I am handy with tools, I just didn't want to start tearing apart his car on his driveway to confirm exactly what the problem is before I bought the car. The noise is coming from under the black plastic cover, sounds like metallic scraping, hard to describe in words. The car runs fine, no missing, backfiring, or lack of power, just the noise. Is noise common before the failure in peoples experience, or does failure of the CAS happen without any warning. Are the replacement CAS better than the originals? Have longer life? This one was replaced once before that I was told about. But I'm not sure if the whole unit was replaced or just the HAS. Has anyone tried to get CAS from Korea directly? Maybe a group buy?

Thanks
Steve

[ashm]

Has anyone tried to get CAS from Korea directly?

What makes you think there are any in Korea?

A nasty noise from the CAS unit will almost certainly be contact between one of the two sensors and the corresponding rotor. More likely to be the HES rotor touching the HES than anything else, particularly as you say it's already been replaced once; it's easy to incorrectly position it, causing contact when running.
If not, then the other likely fault is a dead bearing. This will need replacing; it shouldn't be beyond the skills of a competent mechanic, but you do often need to be careful and have some basic puller/press equipment to replace bearings without damaging them.
It's some time since I took a CAS apart, but I believe the bearing is a 6000-2RSH. McMaster-Carr #5972K81, $7.06.

I'd remove the plastic cover and take a look - the fault will probably be obvious.

Adam

[juneaubehr]

I once saw a photo posted online somewhere of a complete CAS unit beside a box showing the part number and on the box was stamped "Made in Korea", so I assumed that they were made in Korea and may be available in Korea. I know, never ass/u/me.

I will go look at the car again and remove the cover and see what I can see, and maybe take some close-up pics.

Thanks

[steve matthews]

If you are handy and you say you are go for it. 5k + blood and sweat will get you
many hours of enjoyment. Cas. bearing fits in the price. Wheels though I would
request the originals. They can be straightened and refinished. Aftermarket wheels
may look better but they have different offsets. I go for the performance intended with the original
Wheels. Find a good mechanic to consult the rest is in the Wiki.
Best of luck and will await more pictures.
Remember these cars are a HOBIE.
Steve

[juneaubehr]

The car needs the following that I know of; CAS repair, CV joint leftside, seat re-upholstery, timing belt - to be safe, clear coat on the paint is peeling in spots, plus whatever surprises await. I also have two Esprits, so I know what you mean when you say that these cars are hobbys. To me it looks like a fun little reasonable priced convertible to add to the Lotus collection for sunny days and windy roads. My worry about the noise was that it may be something more serios than just the CAS, then it would be sitting on the lift waiting for parts.

[juneaubehr]

Took apart the CAS tonight and found that the noise is coming from the offset cam drive wearing on the washer. (in the photo, the second part from the left rotating against the 3rd part from the left). I layed out the parts as I removed them, starting on the left and moving towards the right in the pic. Does anyone know if this is the correct order? I'm wondering if a previous owner took it apart and re-assembled it incorrectly. I haven't been able to find an exploded diagram of the components anywhere. Once the shaft was removed from the housing I found that there are also 2 seals inside the housing that could be a cause of an oil leak, so I think that I will replace them if I can find replacement parts. One o-ring seals against the bearing and the lipped seal, seals against the shaft. The number marked on the bearing is 6000LU NTN JAPAN, if anyone wants to know. The markings on the lipped shaft seal is IPC 17. If anyone know a source for this seal, I would appreciate knowing. The o-ring that fits in the groove on the outside of the housing and seals against the cylinder head is the same as the speedo drive o-ring. (026F 0287)

[DeanG]

I called a Norfolk Bearing they have the bearings in stock for $10 each. I will try and pick up 2 sets this week so I can rebuild both my CAS.

[Brit-Car-Nut]

The o-ring that fits in the groove on the outside of the housing and seals against the cylinder head is the same as the speedo drive o-ring. (026F 0287)

I do not believe that is true. The Speedo drive o-ring has a smaller cross section and is part number A100F6018F while the CAS (and intake side bung) o-ring is A100E6562S. Do not try to interchange them

[juneaubehr]

I took my bearing in to a local bearing shop and within 2 minutes and less than $10 walked out with a new bearing and new o-rings. To press the old bearing off, I used 2 pieces of 6" long 1/4" key stock layed flat across a vise to support the bearing while pressing on the end of the shaft in a hydraulic press. It didn't take much pressure to move the bearing. After replacing the bearing, seal, o-rings and washers, re-installing it, set the timing, the CAS is still making an awful noise.

[Brit-Car-Nut]

There needs to be a space between the HES and the trigger. Also between the magnetic pickup and the reluctor.

Maybe not very useful, but here is a description of the CAS:



Nothing inside that move should be touching things that don't.

Is it possible that you have the two "washers" between the drive and the body reversed? One is a bearing and one is a spacer. I believe the bearing goes against the CAS body.

[norman lovie]

I have a bit of slop between the cam slot and CAS drive key - not fixed it yet, but I,d be interested if this is your cause - seems to be a bit of one off versus anything common

[juneaubehr]

There needs to be a space between the HES and the trigger. Also between the magnetic pickup and the reluctor.

Nothing inside that move should be touching things that don't.

Is it possible that you have the two "washers" between the drive and the body reversed? One is a bearing and one is a spacer. I believe the bearing goes against the CAS body.

How much space should there be between the pick-up and reluctor, and between the HES and trigger? I can see light between the parts, but have not measured the space with a feeler gauge. The parts in order from the drive end, I have; drive-washer-washer-metal plate with 2 tabs- spring. Both washers are just metal washers, not a bearing, not a bronze thrust washer, not a washer with built in rollers, just flat steel washers. Is this correct? When I took it apart there was considerable wear on the washer next to the drive.

[Brit-Car-Nut]

I just checked a spare CAS and you are correct - the two washers are plain steel. The spring and tabbed plate keep the parts away from contact. The spring is pretty stout. You should have to push hard to move the shaft in and out.

What is the sound you are hearing? Is it a constant grind or a screech or a hum or what?

djcar also lives somewhere nearby, in Vancouver. You might try to contact him to compare sounds? If he doesn't respond to a PM, you can PM me for his email address.

I would expect someone on your side of the continent has a spare CAS they could loan for testing - even if it means placing a deposit to assure them they would get it back without damage.

As far as the gap, I would think that at least 0.005" would be appropriate. It might even run OK at 0.010" . No clue as to what that is in mm, but you can figure that out.

If you can hear a noise when it is running, you should be able to "feel" the cause when it is off the engine. The magnetic pickup will cause a "thump" feel 4X per rotation but it shouldn't feel like something is dragging.

[alan e]

don't know how to put this onto a posting but this may help

[Rambo]

don't know how to put this onto a posting but this may help

What are you trying to attach or post Alan ? A photo or a website link ?? There's nothing visible