Re: Motor has a loud tick

[matt-stunt]

(MOD note: split this off as a new topic since it's a separate conversation about a different engine starting up here)

Turn the engine over with a wrench and see if you can feel the valves touching the pistons, it would feel like hard spots.

I just picked up a 1.6 caddy that had been sitting for 5 years. i started it up it ran for a few seconds then started backfireing out the intake. i figured the timing belt skipped a tooth on the cs pulley so i did a timing belt and reset everything to be timed right.

But while turning the motor over with a wrench to check all the timing marks like you said i hit hard spots. i kind of ignored it because once i broke through the hard spot the engine would turn over like normal. i figured it was just because i stopped turning the engine over when the compression was just about at its hardest point, then when i went to start turning it over again it was just extra hard because i was starting from a dead stop on compression.

anyway when it idles there is a loud tick like is described in the thread

any input?

[rabbitman]

I bet you have a (some) slightly bent valve(s) that hang open and the piston is closing it.

[matt-stunt]

After reading the other thread i tried the injector test where you crack each line when the engines at idle. all four of them made a huge difference in noise. but i don't know it that is because one wasn't firing therefor slowing the engine enough to make the tick sound less violent OR, all four injectors are misfiring and contributing to this madness.

NOTE: the fuel that was in the truck when i got it was horrible! nearly black in color and smelled almost like a mixture of gas and diesel if you could imagine the two together. i had to drain this before it would even hold an idle. possibly thats why the dude parked it? maybe his whife put gas in it or something, could that have anything to do with a valve problem? and if it is an injector problem im sure the crap fuel played a big part in that.

Thanks for the help!

[Vincent Waldon]

You could try running the engine from a jerry can of fresh diesel, just to eliminate bad fuel as a factor in your noise issues.  The challenge is that the nozzles may be a bit mangled... pulling them and having them pop tested is the best way to eliminate them as the primary suspect.

[matt-stunt]

Sorry i didn't make that clear. i did drain every bit of the nasty fuel and added 10 gallons of fresh diesel. as well as replaced the fuel filter

[Mark(The Miser)UK]

Matt,
Here's what I'd do:
On a relatively quiet street, drive along and listen to the ticking.
Does it grow with acceleration?
Does it continue if whilst driving at whatever speed you notice it, most or at least significantly, switch engine off, but leave the engine in gear.
If sound is from injectors only, then it will disappear with injectors off...

In fact if you do it whilst decelerating, initially with engine on and then a direct comparison will be made. 
I have a similar issue, and it is still detectable although somewht diminished with engine off It does not seem to be shim gaps, or even due to my head skim some time ago, and valve clash, so I'm leaning towards the thumping inside the injector pump...

[matt-stunt]

Thanks Mark!

I cant do the road test thing just yet because i haven't put tags on it yet.

But I did do a little more investigating in the shop and while turning the engine over by hand i was able to hear the click. I marked the CS pully and turned the engine over one full revolution at a time and i heard the click in the exact same spot every time. I'm no engine builder but that tells me its not a bent valve because a bent valve would only click every other revolution right? unless it's multiple valves but to me that wouldn't make sense because it was clicking in the exact same spot every time.

Note: when turning the engine over, i would get to the click then turn in reverse direction and would hear the same click every time i passed that spot going clockwise or counter clockwise.

[Mark(The Miser)UK]

Thanks Mark!

I cant do the road test thing just yet because i haven't put tags on it yet.

But I did do a little more investigating in the shop and while turning the engine over by hand i was able to hear the click. I marked the CS pully and turned the engine over one full revolution at a time and i heard the click in the exact same spot every time. I'm no engine builder but that tells me its not a bent valve because a bent valve would only click every other revolution right? unless it's multiple valves but to me that wouldn't make sense because it was clicking in the exact same spot every time.

Note: when turning the engine over, i would get to the click then turn in reverse direction and would hear the same click every time i passed that spot going clockwise or counter clockwise.

... Unless of course the cam is too advanced/retarded then you would catch the same valve on a pair of pistons alternately, eg exhaust valve on #1 then on next rotation exhaust valve on #4.... or perhaps 2 faults in the pump 180 degrees apart

[theman53]

I had one engine that the intermediate shaft bearings were so far gone the shaft would come out about 2" until it stopped on the seal. It made a tick sound. It would only come out if I had the timing belt off but it made the tick every revolution when running.

[Mark(The Miser)UK]

I had one engine that the intermediate shaft bearings were so far gone the shaft would come out about 2" until it stopped on the seal. It made a tick sound. It would only come out if I had the timing belt off but it made the tick every revolution when running.

Interesting:
Was this tick at idle only? Or did it change with loading/slowing?

[theman53]

It was noticable if you looked for it at all RPMs. *guess* I think the engine didn't have much oil pressure and the bearings in the entire engine weren't good. Especially the IM bearings and the thrust washer main bearing and I think one of those 2 places were where the noise was coming from. Didn't get too loud as the engine got louder it was harder to hear.