MOT and HLAs...

[NiceCupOfTea]

MOT today - walked through it without a problem! Yay!

But the bad news - have been suffering bad HLA noise ever since I bought the car. It did very little mileage over the last 6 or 7 years and only had a couple of oil changes in that time (based on mileage not time).

Didn't really notice the HLA noise until after the first service with semi-synth (at an MX5 specialist). Was really really bad, and there 90% of the time (disctict from the usual 5 second rattle on startup). Used some Wynns Hydraulic Lifter de-gunker with little effect. After 3k miles or so I got the oil changed for fully synth with a flush first. It seemed better initially but it's still doing it most of the time. It's now done 2k miles with the fully synth.

When he changed the oil last time my tech said to give it 4k miles and then another change and see how it goes. If not, HLA replacement - although usually only a couple need changing. Today when I spoke to him he seemed to think all would need replacing 16 of them at 30 quid a piece - that's 480 quid on HLAs never mind other parts and labour!!

So, what to do?? I am not spending half the value of the car on sorting the rattling, but having said that it is really, really annoying and makes it sound like a shed. Bad news in a soft top as well. Will a few more flushes/oil changes sort it? How about taking the head off and bunging the HLAs in degreaser and then refitting? Can you replace one or two HLAs?

I'll spend a few hundred getting rid of the noise, but if it's more than 500 quid I won't bother

Trouble is, can't think what I'd replace it with if I did get rid - 944 Cab / TVR S both too expensive and not useable as daily drivers

[GHW]

I don't see a problem with just replacing one or two HLAs. The head doesn't need to come off to do it either - AFAIK you can just whip the cams out and lift them out from above.

There was an article on a Probe/MX6 site about disassembling/cleaning HLAs. I remember it was possible, but very fiddly to get them apart. I'll see if I can dig it out this evening..

[DennisTheMenace]

cant remember if its kia or hyundry but apparently they use the same hla's and they are about £13 each .

[anonymous-user]

This is a good'un.

[GHW]

LexSport said:

This is a good'un.

That's the one!

[steve bowen]

i'd be suprised if they are shot, my car after standing un started for 6 months before I boutght it then 6 months while I turbo'd it was silly noisy but with a bit of oil and thrashing its fine now.

Edited by steve bowen on Thursday 6th September 22:11

[MX-5 Lazza]

steve bowen said:

i'd be suprised if they are shot, my car after standing un started for 6 months before I boutght it then 6 months while I turbo'd it was silly noisy but with a bit of oil and thrashing its fine now.

Edited by steve bowen on Thursday 6th September 22:11

That's a very good point.
If you have HLA clatter, changing the oil then giving it a really good thrashing, making sure the engine gets really hot and using lots of revs (acceleration, not just driving at 60 in 2nd for 5 miles) can help to clear blocked oil-ways.
If this does fix the problem it would probably be wise to change the oil again afterwards to get rid of the gunk.

[NiceCupOfTea]

Yeah, been doing this, believe me!! Will persevere! Any reason why HLAs need replacing rather than cleaning thoroughly?

[MX-5 Lazza]

NiceCupOfTea said:

Any reason why HLAs need replacing rather than cleaning thoroughly?

Not really. I think they can wear out but as long as the car has been regularly serviced and the hla clatter hasn't been going on for too long then they should be fine. I think the reason they generally get replaced rather than cleaned is that it's just easier and if it's being done at a garage it's probably no more expensive when you take time to clean old ones into account.

[redgriff500]

Use a good flushing agent BETWEEN oil changes...

some swear by the additives, I prefer a flushing oil or ATF.

Some swear by (temporarily) using a diesel oil as it contains detergents.

Edit - I see you tried that, try it for longer or some have got better results using a THICKER oil... I guess it depends whether they are blocked or worn ?

Edited by redgriff500 on Monday 10th September 23:57

[NiceCupOfTea]

The car's only done 80000 km, could they really be worn?

[MX-5 Lazza]

NiceCupOfTea said:

The car's only done 80000 km, could they really be worn?

I think wear would be a symptom of poor service rather than mileage. There is no reason why HLA's shouldn't out-last the engine as long as the car has been serviced regularly with good quality oil.

[redgriff500]

First thing is with imports... has it really only done what the clock says.

Secondly poor oil, thrashed from cold....

however none of that matters just try a few different ways to see what works and at the worst replace only the loud ones...

BUT the reason they say to replace them all is because it can be tricky to decide which are the dodgy ones.