Hydraulic tappets

[Brit-Car-Nut]

Best of luck. It is a complicated, simple task (or is that simply complicated) - if you know what you are doing.

[Simon_P]

There is a write-up on how to clean them somewhere here. Try that first.

[Brit-Car-Nut]

You still need to remove the cams to get to them to clean them.

[bbjon]

Hi,

I did this job very a couple of months ago - if you're methodical it's not to bad. As the cams will be coming off it is a good time to pop a new belt on - in the grand scheme of things they aren't expensive and access to the engine mount bolts is so much easier if you don't have the cam pulleys in the way.

If you're determined to not change the belt you can bodge it in finest backstreet garage fashion - zip tie the belt to the cam pulleys before you remove them keep the belt taught and pray it doesn't slip on the crank pulley.
(I DON'T RECOMMEND THIS PAIN WOE AND SUFFERING MAY ENSUE)

Just recharging the tappets didn't seem to make any difference on my car none of them felt spongy when I took them out so It's worth giving them a proper clean.

When it comes to cleaning the tappets - It's worth stripping them completely down. I used a cheap ultrasonic cleaner and did one at a time using a magnet to keep all the bits together - keep an eye on the tiny spring and ball valve. If you need any help with stripping them there are plenty of vid's on Youtube or I can pop out to the garage and take some piccies of one of my spare ones in pieces.

cheers

Jon

[RonR]

Thanks for the tips guys,

The best video I've seen so far is: https://www.youtube.com/watch?v=ySf0r8GGMOY - It's not Lotus / Isuzu specific, but I'm sure all HVLs are similar.

It might be imagination playing tricks but I gave my son a lift to work yesterday and the tappet noise sounded slightly quieter..... Fingers crossed, I might get away with it!

[dapinky]

I've got the video clip for recharging the Lotus HVLs, but as it is slightly over the 2Mb limit for this site I can't add it here.

If it is of any help to you, feel free to give me your email address and I'll send it to you.

[RonR]

Thanks Dave,

PM Sent...

[dapinky]

Email sent

[Brit-Car-Nut]

Both videos are now included in my Manuals link:

The youtube video is "Lifter (tappet) Cleaning & refurb - with verbal instructions" http://www.lotusm100.com/manuals/Lifter ... ifters.mp4

The Short Video Dave mentioned is "Lifter (tappet) Cleaning - Silent" http://www.lotusm100.com/manuals/Lifter ... charge.mp4

They appear to concur on the process but the verbal version gives a lot more information and detailed "How to" video.

[Tanz]

I have just removed the cams so I can clean the tappets. In the service notes, it describes filling the plunger with light oil as engine oil is too viscous (engine EC page 26). In the videos mentioned above they do use engine oil. Has anyone used a light oil? Seems to make sense to do so but what light oil?

[dapinky]

Phil,

The theory with light oil is purely for ensuring that all air is expunged - in use, the oil circulates anyway, so 'normal' oil will soon end up in the tappets.

When I stripped and cleaned mine (many years ago) I did so in parafin, then simply operated them in a bath of warm engine oil (so it was a little less viscous) to fill them.

Have you watched the video of the process??

[Tanz]

Yes, I have seen the video which is very helpful. OK - will give it a go with warm engine oil. There was only one tappet that was particularly noisy but I will do them all while I am in there. Cams look in great shape - no scores or marks. Thanks for the help.

[Tanz]

Made a start on this today. Cleaned them in white spirit and got ready to fill with oil. Very easy to loose those small parts but haven't lost any yet

[Lotus026]

I'm also in the middle of replacing bad hydraulic valve lifters, I'd had several of them in my '89 Isuzu I-Mark RS (same DOHC 1600 as the engine in the normally aspirated M100) which were losing pressure after being parked but would eventually pump up - until not, on a warm day returning home from 350 miles away! So one very expensive return home with dead car towed behind rental truck.

Isuzu used the hydraulic lifters on the '89 engine for the I-Mark, but then switched to shimmed valve followers for the same engine in the Geo Storm / Isuzu Impulse for '90-'91 and gained several hp because of the lighter weight of the shimmed followers. Then switched back to hydraulic again in '92-'93, while also increasing capacity to 1800cc and keeping about the same hp - though the turbo version of the engine used in the Impulse RS AWD version always used the 1600 & shimmed valve followers, Lotus must have specified the hydraulic ones for ease of maintenance / being quieter.

Confused yet? I was! Trying to find replacement hydraulic followers was extremely difficult, everyone sold the shimmed version but not the hydraulic; until I spent the better part of a day cross referencing GM part numbers - which turned out to be a direct cross to the Suzuki followers, also fit many other OHC cars. I would have switched to the shimmed followers (in fact, that was what I was first sent as replacements; the seller had them described wrong and applied the wrong part number to them) for the performance advantage, but the adjustment shims are even more difficult to find - and cost far more than the followers themselves!! About $15 - $20 each, US. Most of the good info I found about them was through Geo Storm websites, since that's where most of the production in the US ended up going; the Isuzu versions were relatively rare in comparison, the turbo Impulse RS even rarer.

[brijo]

In a few weeks time I intend to replace the cam belt. At the same time I would like to remove the cams to give the hydraulic lifters a good clean.

I was hoping to watch the videos that BCN had mentioned above but I’m aware that he has withdrawn from the forum and the links he supplied are now broken.

Would I be right in thinking that the first video, “Lifter cleaning & refurb – with verbal instructions” is the one by Alex Espinosa https://youtu.be/ySf0r8GGMOY If not does anybody know where I can access this video please?

There is another video mentioned, “Lifter cleaning – silent”. Does anybody know if this is available anywhere?

Brian

[dapinky]

Hi Brian,

If you go to the 'Manuals' link at the top of the page, scroll down past the actual manuals to the "Useful Documents" section, there is a video on there showing the procedure.

[brijo]

Hi Dave,

Thank you for the info. I did glance in that section before I posted but I was looking at the titles at the bottom of the thumbnails and I missed the video. I need my specs cleaned as well as my HVLs.

Brian

[dapinky]

Hi Dave,

Thank you for the info. I did glance in that section before I posted but I was looking at the titles at the bottom of the thumbnails and I missed the video. I need my specs cleaned as well as my HVLs.

Brian

Whilst I could just agree that you're blind, that would be unfair....... I only added it after I saw your post, and it's the easiest way to host a video!

[Dave Eds]