oil additive

[gov]

I change the oil regularly and use 10/60 Castrol Edge but like most Elans if left for a few days have some tappet noise on start up - only for a minute or so but still annoying - is there anything on the market that you could add safely to the oil that could help eliminate this ?

[Motocompo]

Same problem here. Also using Castrol 10W 60.

I have around 90.000km on it and change the oil every year which is around every 3.000km...

[HJ2]

There is a whole list in the wiki concerning oil and tappet noise.
You could try adding TSL, but that said i don’t think that will help the tappet noise much.
It is used by a couple of Lotus Racing Teams with good results though.
Perhaps a thinner oil from cold will fill the tappets faster.
I just finished dissasembling, ultrasonic cleaning, polishing and priming a full set of tappets and hope to post the results soon (not my car)
On my own car the tapping was gone after this procedure.

[Rocklobster]

One train of thought says don't use 10W60. The 10 denotes the viscosity from cold. The lower the number, the less viscous. I use Mobil 1, 0W40 because it's less viscous from cold, it flows readily and gets around the engine (including into the hydraulic tappets) as soon as you start the engine whereas a 10 grade will take longer as it needs to warm up slightly. The worst I get is a slight tappet rustle for five seconds after it's been left for a week, other than that, it's as quiet as a mouse.

For what it's worth, the 60 grade is a measure of the viscosity at (I think) 100 deg C. Again, the higher the number, the more viscous, so if you use a higher viscosity, whilst your oil pressure will look healthy, the oil won't flow as readily as a thinner oil and it may not be lubricating as well as a slightly thinner oil.

Some people are concerned about oil leaks or oil pressure dropping with a thinner oil but mine's got 95,000 on the clock, no leaks and good pressure. Google it, I'd recommend changing youyr oil grade.

[Neil D.]

Anybody here fitted an accsump to prevent tappet noise at start up ?
Thanks
Neil

[HJ2]

How would that work? (no experience, sorry!)

I rather fix the cause then the symptom.

[Neil D.]

An auxiliary, pump and reservoir, prime and pressurise the engine before start up.
It is used a lot on race cars,
Check their web site
Neil

[HJ2]

That doesn’t sound nessecary at all.
Try changing the oil grade or else recondition the lifters would be my approach.

[Rocklobster]

An auxiliary, pump and reservoir, prime and pressurise the engine before start up.
It is used a lot on race cars,
Check their web site
Neil

This does look like an awful lot of expense when a simple oil grade change will do. If you're experiencing excessive valve clatter at start-up, then either your engine oil is too thick a grade or your hydraulic lifters are worn or dirty (or on an older engine, your tappets need adjusting).

The reasons race and drag teams use Accusump are because they suffer with oil surge & starvation due to extreme acceleration/braking/cornering forces and some (e.g. Nascar) also run greater engine clearances to cope with the temperature gradient, so they need a system to compensate for oil starvation and to flood the top end at start-up. Shouldn't be necessary on a road car.

[Simon_P]

As mentioned above try a 5/10W30 or 40 oil. I have found that low cold viscosity can also cause noise.

The tappets use oil pressure to pump them up. Dirty tappets leak oil out when the engine is stopped, so require "pumping up" when the engine is started from cold. I'd suggest that your oil is too thick when cold to get back to where it should be quickly.

I think the filter has an anti drain valve and there is a non return valve in the head so the system doesn't need priming. Your problem might be worse due to the viscous oil being dumped back into the sump by the pressure relief valve on the pump.

[shirt]

my experience of oil threads is that its pointless commenting as 10 posters will give 10 different answers. usually comes down to preference [its what i always use etc] rather than fact.

however:

generally i would simply recommend a high quality oil as per manufacturer recommendations and regular oil and regular changes. the blurb about these recommendations on the wiki is a load of bumf.

lotus' recommendation on the upper SAE viscosity grade is a 30 or 40 weight. the jumps between steps [30,40,50 etc] sees roughly 20% increase in viscosity @ 100degC. hence an SAE60 upper viscosity grade means that the viscosity at 100degC is 40% greater than lotus highest SAE' recommendation. this is far too great a difference. i would go for SAE50 max. if you track the car or regularly see high oil temps, otherwise 40.

on the low temp range there isn't much of a difference between 0W and 10W,the jump to 15W is also small and 15/20 are identical. here i would go with a lower number as possible coupled with a high viscosity index [from the spec sheet]. the viscosity index is a measure of stability across the temperature range, the higher the better.

personally i think i'd go with a classic performance oil with zinc additives. a quick google suggests 20w50 motul classic performance would be the choice as it has ZDDP additives, a decent visco index for a none FS oil, and it's motul which is my preference

[HJ2]

Excellent! Another opinion to add to the wiki then
Let us know what the swap to this oil brought you in terms of tappet filling rate.
That might shed some light on this for future readers

[dapinky]

Oil theories (and facts!) are always plentiful in any motoring forum..... but I fully accept the %ages raised at 100C.

The obvious difficulty comes in recommending an oil, when all cars are driven differently - both mileages and 'aggresiveness' - during the 12 months between changes.

When i was doing a lot of competition driving, the oil would be changed between each event, and always Castrol GTX 20w50 (that's how long ago it was ). But my road car had the same oil, but it lasted 6 months between changes..... Again, that was in the days when there were fewer options on the shelf, and TBL hadn't invented the WWW.

I hate to recomend an oil to anyone - but I am happy to state what I use, and why I use it. This isn't the same as stating that I am right, but it is just what I use at the moment.

I am happy with the way my car runs on Fuchs 10w60 - and I find that the top-end viscosity is fine for my car, as it has high mileage and associated wear..... but it may not be great in a car with 50K miles. When I was using 'thinner' oil, my oil pressures were far lower than I would like to see, but now I'm happy with the readings.

[shirt]

maybe bumf wasn't the right word. i meant that the line about oil technology moving on since the elan's build is misleading. modern oils are for modern engines. the oils employed during the elan's birth would still be perfectly fine if 4 star was still around. i wouldn't put an ester based fully synth oil and super unleaded into a car designed for dino oil and 4 star and expect it to have the same engine wear after X miles. i don't see a 100bhp/litre car needing a race spec oil either, but good point on the thicker oil benefiting a high miler.

for the OP, adding a friction modifying additive will get you to the next oil change if its had a recent service, but after that its better to simply use a thinner oil. additives sold as curing tappet noise tend to be detergent modifiers and act by cleaning the oil paths. this might also help the thicker oil flow better at startup but depends how clean things were to start with. avoid any other additives. i see a lot of oil wear-check reports, if they worked then the oil companies would be using them.

[Fetnas]

On the tappet noise issue, when I replaced the head gasket over 2 years ago, I had my dad dismantle and clean out all the hydraulic tappets. I would have done this myself, but i have 2 small children that make finding the time for this kind of work very difficult.

A high quality fully synthetic 10w50 oil was used to prefill the tappets, and is the oil in the car. After sitting for an embarrassingly long period of not being used (see the small children excuse) the car starts with no tappet noise at all. It did take a couple of cycles of running after the initial assembly for the final bubbles to be purged from the tappets, but since then, the tappets have remained pumped up.

It's a big job to do as there are 16 tappets, and each has i think 6 components, some of which are tiny, but worth it if the engine is already apart. I also had the head ultrasonically cleaned to remove any deposits from the oil passages, and cleaned every other part I could, so there should be fewer particles floating around that could jamb in the tappet valve open and allow the oil to drain out.

If an engine is only tappety on start up and quickly settles, I wouldn't go to this level of effort to clean the lifters, but if the engine is already apart, it makes sense to give it the full treatment. Just my 2 cents.

[Simon_P]

lotus' recommendation on the upper SAE viscosity grade is a 30 or 40 weight. the jumps between steps [30,40,50 etc] sees roughly 20% increase in viscosity @ 100degC. hence an SAE60 upper viscosity grade means that the viscosity at 100degC is 40% greater than lotus highest SAE' recommendation. this is far too great a difference.

Lotus' published a recommendation for 10W/60 hence its widespread use and the OPs question.

on the low temp range there isn't much of a difference between 0W and 10W,the jump to 15W is also small and 15/20 are identical. here i would go with a lower number as possible coupled with a high viscosity index [from the spec sheet]. the viscosity index is a measure of stability across the temperature range, the higher the better.

I think that you may have misunderstood something here. At 20C 10W/30 is about 200 cSt and your 20W/50 is about 600 cSt. At 100C 10W/30 is 10.5 cSt and 20W/50 is 19 cSt.
Your comment on viscosity index doesn't make sense to me in relation to a multigrade oil.
You say you'd go with a low W number then recommend a 20W

personally i think i'd go with a classic performance oil with zinc additives. a quick google suggests 20w50 motul classic performance would be the choice as it has ZDDP additives

That might be a good recommendation for a 60's elan. No need for a ZDDP additive on an M100 and it will last much longer with fully synthetic - almost no journal wear at 100k miles.

a car designed for dino oil and 4 star

The M100 was designed for unleaded. The preferred oils for the S2 were fully synth 10W 60 or 5W/50 the last recommendation was fully synth 0W/40

[HJ2]

To add to the discussion:

Yesterday I started the engine of the steel blue after a rebuild.
As you can see in my running topic the hydraulic valve lifters have been dissasembeled and cleaned (forum.lotuselancentral.com/viewtopic.php?f=79&t=28322)

The lifters were primed with 5W40 full synthetic and the rest was poured in the freshly welded oil pan
After 2 seconds or so everything was quiet and stayed quiet. even after a few restarts.
Now this is the 4th time that i have done this and all 4 cars have quiet lifters. Not all cars have the same oil viscosit though. Yet all of the engines are quiet.

So again: Try a lower viscosity from cold to help fill the tappets. If that does not work: take them apart and clean them.
Please post the results.

[shirt]

I think that you may have misunderstood something here.

quite possibly lol.

by 'personally' i meant the definition of that. its 25degC on a cold day where i live.

[Motocompo]

Same problem here, using also Castrol 10W60.
When the engine is cold and the car stood some while there is this tappet noise fore some minutes.
When the engine is hot everything is fine and the engine sounds as it should.

There is an additive from Liqui Moly, it´s called LIQUI MOLY 1009 Hydrostößel Additiv 300 ml
and it seems to help.

Anyway, I don´t believe in additives and I will not use it.

Instead, I checked the service bulletin of the S2 and it says that they recommend Mobil 1 5W 50.
I will switch from the Castrol 10W60 to the Mobil1 5W50. Hopefully it will help.

[Motocompo]

Starting my car last week after 5 months the tapping noise was magically away.

I now changed the oil and put Mobil1 5W50 into it and still everything is silent, even when starting cold.

I topped the oil between min. and max. on the scale, not on max. as earlier.

Maybe (just maybe) this is the solution.