Has any one been playing with timing recently? mk1 1600

[dylan0451]

adjusted my timing to 14 degrees sometime last year - reduced backfire when shifting up, generally felt good

had a ticking develop recently. doesn't do it all the time, only usually at it's loudest when the engine is warm

thought an oil change might be in order since its been atleast 5k miles since the last one

also put some wynns engine flush through that's supposed to quieten noisy lifters but it's made no difference

the ticking is directly related to engine speed though sounds slow, so i was thinking maybe injector? but since i'm mentioning timing i'm also wondering if there's a possibility of pre ignition? since i've never had a turbo car i don't really know what it sounds like, though i would have thought the engine would feel a little hesitant at low revs, and i would have blown it to bits by now?!

am gonna borrow a strobe and set it back to 10 degrees and see if the noise goes away, but as above, i'm doubtful it's ignition - 95ron on a hot day/98ron on a cold day/tank either brimmed or empty - noise always remians the same

thoughts chaps?

[MX-5 Lazza]

It's definitely not pre-ignition and not likely to be related to ignition timing (so don't bother adjusting it back). It's most likely to be "normal" HLA tapping though in your case it sounds like one of the lifters might be stuck. I'm sure someone will be along soon enough to tell you how to free it up or replace it

Edited by MX-5 Lazza on Monday 6th September 18:42

[dylan0451]

i thought i'd mention it since the noise is closest to the bulkhead, so i was assuming no.4 cylinder which runs hottest might have not liked the advance, though i'm sure i've read somewhere the scca(?) guys run up to 17/18 degrees advance for, i assume, a raised rev limit.

i've heard of adding small amounts of ATF, other lifter un sticker products etc. but it may well be something i'll have to live with, i guess i can continue to use a flush at every oil change, or go to a thicker summer grade oil maybe

[MX-5 Lazza]

Pre-ignition is most likely around peak torque so around 5500-6000 rpm. Timing would have to be massively out to get any at idle

I know some will frown at this but using diesel engine oil for a short spell can do wonders too. It's a bit harsh on the seals so don't leave it in too long.

Which oil do you use? Mobil1 0-40 is great for freeing up lifters and keeping them free

ETA:
Just re-read your original post...

dylan0451 said:

adjusted my timing to 14 degrees sometime last year - reduced backfire when shifting up, generally felt good

Advancing the timing reduced a backfire? Sounds to me like you might have another problem skulking away in there somewhere. The only reasons for a backfire would be timing too far advanced (no, I mean really advanced, so far that it would be difficult to drive and probably wouldn't idle) or over fuelling (which is the most likely cause).
Over-fuelling is likely to be either a faulty O2 sensor or coolant temp sensor (the one on the back of the block). Advancing timing shouldn't really affect it.

Maybe Mazdamender could offer some advice here too

Edited by MX-5 Lazza on Tuesday 7th September 12:13

[snotrag]

RE lifters - The key for me was changing to Mobil 1 0-40, gives me about 4000 miles before the tap dancers come back.

I did at one point have a lifter that 'stuck' and I couldnt shut it up - I seem to recall that I fixed it by gettign the car really nice and hot (good thrashing) and then dropping the oil straight after (be careful!) and re-filling.

I tried that HLA stuff and I think it justs thins the oil when cold to allow it to pressurise the lifters more easily.

[dylan0451]

hmm...

i've been using mobil 1 0w-40 and done about 3-4 changes now. it has reduced HLA clatter on startup - used to last about 3 secs or so when i was running the vavoline 5w50 that the guy who sold me the car said to use.

the clatter i get now was never there when i bought the car - it's most apparent on wider throttle openings at lower rpm say 1500-4000 but generally across the range

the last change, again using the mobil 1 i used some lifter freeing/engine flush stuff and it made no difference at all. it is worth mentioning the clatter is more noticeable when the engine is hot, i'm wondering if this is why the previous owner changed to a thicker hot grade oil as it remains slightly thicker at 100c