V6 Ticking Noise but HLA's are FINE????

SpudgunBlunder · Post by **SpudgunBlunder** » May 29th, 2007, 9:21 am

Started the car one day and it sounded like old farmer Giles' Tractor. A loud ticking sound coming from the right side (back) of the engine, near cylinder 1.
The noise clears if i rev over 1750rmp.

What else could be causing the ticking noise if all the HLA's are fine (NOT compressable - B2-80). Could it just be low oil pressure? There's no light on though and it's full of oil.

Oil or water pump?

This car drives me crazy. Time to take it out back like old yella. (BOOM)

What about replacing the 1.8 V6 for a 1993 MX-6 KL Engine 2.5 V6?

Post by **Custommx3** » May 29th, 2007, 9:32 am

Could be timing belt tensioner, the pin in your cam gear, or your cam friction gear spring.

hgallegos915 · Post by **hgallegos915** » May 29th, 2007, 4:06 pm

X2 on the timing belt tensioner.

neutral · Post by **neutral** » May 29th, 2007, 5:34 pm

hgallegos915 wrote:X2 on the timing belt tensioner.

X3

SpudgunBlunder · Post by **SpudgunBlunder** » May 29th, 2007, 6:19 pm

Thanks for the good suggestions guys.

I can't diagnose anything until the weekend because the car is under my parents garage (2 hrs away) but I asked my dad to take a quick look at the timng belt tensioner and he said the bearing seems fine.

cam friction gear spring

I take it you mean the sprung 2nd cog on the "slave" cam. I can't find any info on this in the online manual or in my mx-3 workshop book.
From what my dad ays, the two cogs are solid and can't be moved by hand. I'll ask him to try with a bit more force to see if these are free to move but still sprung.

I don't remember seeing any pins on the cams except maybe a pic in my book (which I left with the car - dohh) of the timing pully attaching to the cam. Is the pin holding the cam spring?

Thanks for your help.

lakersfan1 · Post by **lakersfan1** » May 29th, 2007, 10:44 pm

SpudgunBlunder wrote: I asked my dad to take a quick look at the timng belt tensioner and he said the bearing seems fine..

We mean the hydraulic tensioner that pushes on the tensioner bearing arm. It should require several hundred pounds of pressure to compress the arm.

cam friction gear spring

I take it you mean the sprung 2nd cog on the "slave" cam. I can't find any info on this in the online manual or in my mx-3 workshop book.
From what my dad ays, the two cogs are solid and can't be moved by hand. I'll ask him to try with a bit more force to see if these are free to move but still sprung.[/quote]

Where the exhaust and intake sprockets mesh together under each head, one of the cogs will have two sets of sprockets on one axis. The thinner sprocket on the end of the cam is the friction gear.

SpudgunBlunder · Post by **SpudgunBlunder** » June 1st, 2007, 4:58 am

I've been reading a bit more:
Could this be rod knock/top ends?
Although if it was, the noise would just increase in pitch (frequency) as I rev the engine. The noise in my situation seemed to suddenly go when reved over about 1700rpm hot or cold.

Is it worth taking off the oil pan to check?

SpudgunBlunder · Post by **SpudgunBlunder** » June 5th, 2007, 7:30 pm

I took another look at my engine at the weekend but couldn't find anything that would be causing this ticking noise!

The friction gears we're both fine.
Cam fine.
All HLA's fine.
Cam belt tensioner seemed a little weak but not letting the belt be slack.

So I built it back up and started her up a recorded a video with my brother's camcorded. But I don't have firewire or a DV cable so here's just an mp3 of the recording.

http://www.wikiupload.com/comment.php?id=154251

It's a few minutes long but please listen because the ticking noise gradually gets louder then suddenly quietens at intervals.
You can also hear the noise die away as I rev the engine.
The car was already warm before I started it up when I recorded this.

What the hell is up with this car?

Is it something to do with oil pressure causing a HLA tap?
Is it rod knock?
Is it piston slap?
Is it belt tensioner?
Is it oil/water pump?

SpudgunBlunder · Post by **SpudgunBlunder** » June 7th, 2007, 2:35 am

here's the full version:

http://www.mediafire.com/?6uzssvtvzrg

Whisper · Post by **Whisper** » June 7th, 2007, 2:56 am

Wow, that does sound like a tractor. Or a diesel truck, even. Maybe you have a diesel engine? Heh.

Doesn't sound like HLAs to me. I've no idea. Right side of the block you say? What the hell is down there? P/S oil pump, buncha pulleys. My guess would be one of the pumps is borked. Does it sound like it's coming from inside the engine, or from around it?

94mx3precidia · Post by **94mx3precidia** » June 7th, 2007, 9:09 pm

3 mins into the clip, were you reving it from your car or from the throttle control under the hood?

That sounds nasty man, almost kinda like piston slap. Dont take me as a pro though, i only really know sounds from motocross bikes.

the movie might be helpful though.

lakersfan1 · Post by **lakersfan1** » June 7th, 2007, 9:39 pm

SpudgunBlunder wrote: Cam belt tensioner seemed a little weak but not letting the belt be slack.

It shouldn't be weak at all. It takes literally HUNDREDS of pounds to compress it. If you stood a 300 lb man on top of the hydraulic tensioner, it wouldn't move a BIT. the only way I can compress it without bringing it to a machine shop is I put the tensioner between the frame of my car and a jack. The tensioner doesn't go down on my healthy tensioner until the full weight of the front of my car is on the tensioner. It's a real PITA. I can't move it at ALL with simple hand tools or vices.

94mx3precidia · Post by **94mx3precidia** » June 7th, 2007, 9:41 pm

[quote="lakersfan1"]I can't move it at ALL with simple hand tools or vices.[/quote]

i guess thats a good thing?

SpudgunBlunder · Post by **SpudgunBlunder** » June 8th, 2007, 4:31 am

I've searched for every video on youtube etc for "rod knock", "piston slap", "tappet/lifter noise" and I think the noise is top end rather than rod knock which is a deeper sound and lower in the engine, am I right? (never heard it in person) I did'nt think it was piston slap as that's more of a rattling noise, am I right?

Maybe I just want to hear something that doesn't mean a bust engine.

3 mins into the clip, were you reving it from your car or from the throttle control under the hood?

I start the car and rev it from inside for a minute. Then you can tell when I walk round to the engine (under the hood).

I bought 3 replacement (2nd hand) HLA's and one was actually weak/compressible. I could compress that one quite easily with finger and thumb and when I repeatedly compressed it in a glass of clean oil I could see air bubbles being forced out. It got stiffer as I expelled the air but it was still not solid like the others.

I've been reading this:
http://forums.probetalk.com/showthread.php?t=1701019093

and I think my problem could be caused by low oil pressure due to using the wrong grade oil 15w-40 and a few instances of the engine badly overheating. I think this could have caused deposits and therefore a blockage or restriction. I could scrape "crud" off the top of my cam covers with my finger nails. Could something like this have happened?

How can I test I have a good flow of oil to the HLA's without taking off the head?

What product should I use to flush the poo bits of oil out when I do an oil change or should I not use anything? I've been told that I'll do damage than good.

I will try and do an oil pressure test but will that not just tell me pressure of the whole system and not indicate any single blocked HLA gallery.

I will post the video if I can but can't get the dam VIVO working on my ati card and I don't have a DV cable or firewire.

Thanks for reading and commenting on my

's

SpudgunBlunder · Post by **SpudgunBlunder** » June 8th, 2007, 5:26 am

I was wondering if I could determine whether it was rod knock or HLA tap by the frequency of the tapping.

If the engine idles at 650rpm = 650/60 rps = 10.83 rps i.e. the crank shaft revolves 10.83 times every second,

and the crank:cam ratio is 2:1,

then the cam revolves at 5.42 rps,

therefore a tick sound should be heard every 0.185 seconds.
or 5.42 every second or 11 every 2 seconds.

Whereas rod knock would be every 0.092 seconds or 10.83 every second.

Oh poo.
Just realised that rod knock would occur twice every crank rev. i.e. once every stroke. So for every 1 tick of the cam you'd hear 4 rod knocks.

But then it's possible/probable that both inlet and exhaust HLA's are ticking so it'd be twice the frequency.

Think I'm thinking about this too much?