Horrendous valve train/HLA noise
Discussion
Right, I know this has been covered plenty of times, and I've read plenty of stuff on the subject already. But I thought I could do with some fresh ears.
The car was fine when I bought it. I covered about 300 mixed miles the week I bought it, then it sat in my garage for about 5 weeks. It began to make noise on the last day as I put it away, but as I'd read about it plenty of times I just assumed it was the HLAs and it all seemed to make sense.
Anyway, today, Fired it up, its very noisy now.
I've just changed the oil, added some Wynn's HLA treatment, let the car warm up a few times, and its still there. Admittedly its not actually run that long, and I'm not insured yet so can't drive it further than 100mtrs down the private driveway (ahem).
It smoked a bit too when I first started it, which also suggests to me that a Valve is sticking or perhaps not seating down quite properly?
Other than the noise, then engine actually sounds and feels quite healthy - oil pressure if fine, temp is fine, it revs up and down cleanly, solid idle etc. Other than the very distinctive tapping the engine sounds fine. Just like it was the week I bought it, less than a hundred miles ago.
Its certainly coming from the head and you can hear it through the filler cap if you take it off. So I'm pretty confident its nothing dramatic like a bearing in the block, and theres no leaks that I can see.
The oil that came out, despite supposedly not being that old, was pretty black and grotty.
Wisely - I've not filled it with Mobil 1. I've used some reasonably quality semi-synth, on the assumption that I may well be flushing it through again very soon.
Reccomendations? I'm a little bit loathe to try the 'italian tune-up' method unless I'm more confident that it should do the trick. Time and a few miles? How long shall I leave it before flushing it through with another lot of oil?
If I get a compression test done, that would show a sticking/badly seated valve up as an erroneously low pressure on one cylinder (The frequency of the tapping is such that i think its just 1 of 16 that is stuck) ?
I'm not too keen on putting any very strong oil flush additives in it as its 14yrs and 80 thousand miles old.
ETA - here it is - http://flickr.com/photos/simonholehan/3148337148/ Sound quality not that great unfortunately.
The car was fine when I bought it. I covered about 300 mixed miles the week I bought it, then it sat in my garage for about 5 weeks. It began to make noise on the last day as I put it away, but as I'd read about it plenty of times I just assumed it was the HLAs and it all seemed to make sense.
Anyway, today, Fired it up, its very noisy now.
I've just changed the oil, added some Wynn's HLA treatment, let the car warm up a few times, and its still there. Admittedly its not actually run that long, and I'm not insured yet so can't drive it further than 100mtrs down the private driveway (ahem).
It smoked a bit too when I first started it, which also suggests to me that a Valve is sticking or perhaps not seating down quite properly?
Other than the noise, then engine actually sounds and feels quite healthy - oil pressure if fine, temp is fine, it revs up and down cleanly, solid idle etc. Other than the very distinctive tapping the engine sounds fine. Just like it was the week I bought it, less than a hundred miles ago.
Its certainly coming from the head and you can hear it through the filler cap if you take it off. So I'm pretty confident its nothing dramatic like a bearing in the block, and theres no leaks that I can see.
The oil that came out, despite supposedly not being that old, was pretty black and grotty.
Wisely - I've not filled it with Mobil 1. I've used some reasonably quality semi-synth, on the assumption that I may well be flushing it through again very soon.
Reccomendations? I'm a little bit loathe to try the 'italian tune-up' method unless I'm more confident that it should do the trick. Time and a few miles? How long shall I leave it before flushing it through with another lot of oil?
If I get a compression test done, that would show a sticking/badly seated valve up as an erroneously low pressure on one cylinder (The frequency of the tapping is such that i think its just 1 of 16 that is stuck) ?
I'm not too keen on putting any very strong oil flush additives in it as its 14yrs and 80 thousand miles old.
ETA - here it is - http://flickr.com/photos/simonholehan/3148337148/ Sound quality not that great unfortunately.
Edited by snotrag on Monday 29th December 19:01
One HLA on my recon engine was stuck when I fired it up for the first time, sounded like a jackhammer, but after running it to normal temperature and then leaving it to get stone cold over a few days it released and has been quiet since, just the normal second or so of quiet tapping at startup as the HLAs fill up.
Seems like old HLAs get gunked up with old oil, so perhaps you should remove all the HLAs and clean them - instructions here:
http://www.miata.net/garage/hla/cleaning.html
I took all the HLAs out of my spare engine and they're pretty simple to pull apart and clean, just 2 little pots and a small spring.
You could pull the cam cover off and see if you can locate the stuck one with feeler gauges under the cam lobe - maybe there will be a visually obvious gap under the cam lobe?
Seems like old HLAs get gunked up with old oil, so perhaps you should remove all the HLAs and clean them - instructions here:
http://www.miata.net/garage/hla/cleaning.html
I took all the HLAs out of my spare engine and they're pretty simple to pull apart and clean, just 2 little pots and a small spring.
You could pull the cam cover off and see if you can locate the stuck one with feeler gauges under the cam lobe - maybe there will be a visually obvious gap under the cam lobe?
Its been suggested on another forum that it may not the Valvetrain and could be the wobbly pulley thing - Im going to check tomorrow but I'm pretty sure, and rather more hopeful, that its not that!
So if it is the Valves - taking the cam cover seems like a good idea as I presume its pretty easy - new seals required?
If I do take the Tappets out to clean - I presume the process is remove cam cover, then the cams will need to be lifted out too - which involves disturbing the timing belt. So, I may aswell do that at the same time, rather than trying to refit an old belt in the right place...?
So if it is the Valves - taking the cam cover seems like a good idea as I presume its pretty easy - new seals required?
If I do take the Tappets out to clean - I presume the process is remove cam cover, then the cams will need to be lifted out too - which involves disturbing the timing belt. So, I may aswell do that at the same time, rather than trying to refit an old belt in the right place...?
Doesn't sound like the crank nose-pulley wobble to me.
Wynns isn't a particularly strong engine flush, fine for normal oil-changes but if you are trying to solve a problem like this you need something stronger like Forte Engine Flush. Alternatively try running diesel oil through it as a flushing agent.
Wynns isn't a particularly strong engine flush, fine for normal oil-changes but if you are trying to solve a problem like this you need something stronger like Forte Engine Flush. Alternatively try running diesel oil through it as a flushing agent.
Its the Wynns hydraulic tappet treatment thats in there, was recommended. I only added it after letting the engine run for a while initially - It doesnt seem to have done a huge amount but we will see.
As for doing a full on engine flush, I'm still not sold. If there IS goop in my oilways and bores, then I'm not sure I want to move it. its just the area round the tappets and the valve seats that bothers me!
As for doing a full on engine flush, I'm still not sold. If there IS goop in my oilways and bores, then I'm not sure I want to move it. its just the area round the tappets and the valve seats that bothers me!
You might as well fit a new cambelt and probably change the waterpump as well as they're pretty cheap things. A cambelt kit should include a new idler pulley and tension spring also. A new camcover gasket just pushes into the slot before refitting, remember to add a little squirt of silicone sealer at the corners around the camshaft end caps.
I use these 2 books as reference:
http://www.amazon.co.uk/Do-Up-Practical-Renovation...
http://www.amazon.co.uk/Mazda-MX5-1-6-Workshop-Man...
If your engine is one of the older ones with the 4-slot crank pulley you need to be careful about disturbing the crank bolt - I believe you can change the cambelt without neeing to remove the bolt on that design of crank.
I use these 2 books as reference:
http://www.amazon.co.uk/Do-Up-Practical-Renovation...
http://www.amazon.co.uk/Mazda-MX5-1-6-Workshop-Man...
If your engine is one of the older ones with the 4-slot crank pulley you need to be careful about disturbing the crank bolt - I believe you can change the cambelt without neeing to remove the bolt on that design of crank.
The pulley was rock solid in all directions, belts all felt fine too.
So I started it... and after about 5 seconds the noise fell to a tenth of what it was yesterday. Sorted. I'll run it for a few hundred miles then change the oil again, If I then change it regularly I guess I should be able to keep it at bay for most of the time.
So I started it... and after about 5 seconds the noise fell to a tenth of what it was yesterday. Sorted. I'll run it for a few hundred miles then change the oil again, If I then change it regularly I guess I should be able to keep it at bay for most of the time.
I had quite bad HLA noise on my mk 1 Eunos, would sound like the entire engine was literally falling apart for the first ten mins of any journey. I managed to cure it by, warming up the engine thoroughly, running a wynn's engine flush through it, for 20 mins I think? Changed the oil to some cheap crappy 20w-50 spec. Run this oil for about 100 miles, made sure I did this mileage in about 2 days. Then ran another engine flush through it and re-filled with fully synthetic 5w-40 oil, the noise never came back!! Plus it didnt cost the earth, so even if it didnt work it wasnt the end of the world?
Mine were terrible (seems same experience as JimSuperSix) when I'd rebuild the head. It did take a good drive before it settled down, then quiet as a mouse.
When my mum had the car before me, it used to stand sometimes for a few weeks, generally the same thing happened. Less so these days, although I do more miles in it and change the oil relatively frequently.
So - needs a long drive as most likely/easy cure!
When my mum had the car before me, it used to stand sometimes for a few weeks, generally the same thing happened. Less so these days, although I do more miles in it and change the oil relatively frequently.
So - needs a long drive as most likely/easy cure!
Panic over. Went out today in the freezing cold. Slight tapping as I rolled out the garage, after 10 minutes it was warmed up and far smoother. did about 70 miles on B-roads, the engine was working fine. Can't wait to get some 15's and decent tyres on though! And I'm gonna book in for alignment ASAP. Thanks to the tyres and the very slick, cold roads, a quite high proportion of the 70 miles was with wheel spin. It spins out of every T junction, its almost farcical. Diff must be working well as you can hold it very easily!
All said and done - I'm chuffed it seems to be working well now and I can finally drive it. Well aware I need to be very careful at first though, I would like to keep this car for a while!
All said and done - I'm chuffed it seems to be working well now and I can finally drive it. Well aware I need to be very careful at first though, I would like to keep this car for a while!
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