what makes slight tck soynd when cold..?

[kevinm]

I have around 600 km on this completely rebuilt motor and still have a sound I can't put my finger on..happens when cold and gone when warm.. doesn't sound like lifters.. it def. Not as loud as lifters... The injectors were rebuilt but one is leaking a bit from I don't know where yet.. do injectors sometimes sound like a slight tick when cold.. and at random times.. when this motor is up to temp it sounds mint..

[R.O.R-2.0]

I have around 600 km on this completely rebuilt motor and still have a sound I can't put my finger on..happens when cold and gone when warm.. doesn't sound like lifters.. it def. Not as loud as lifters... The injectors were rebuilt but one is leaking a bit from I don't know where yet.. do injectors sometimes sound like a slight tick when cold.. and at random times.. when this motor is up to temp it sounds mint..

if it has hydro lifters, i would still suspect them..

what weight oil you running?

did you put a new timing tensioner on it as well?

ive had timing tensioners knock before..

[Gizmoman]

Kevinm, I'm no expert by any means and don't want to worry you - but what kind of shape were the precups in when you installed the head? Possibly when it warms up (if one were slightly loose) it tightens up when it gets warm.

[theman53]

That is good point about the precups.

FWIW mine had a slight tick when it was really cold. Almost like a gasser ping, but it didn't need to warm up completely. If you just ran it or let it idle for 30 seconds it was gone. I attributed it to everything being new on the engine and tight. After 6,000 miles I didn't notice it anymore, but I really wasn't concerned about it either.

[kevinm]

I got the head machined with the old precups in... And yes they were all a little cracked.. maybe its worth taking the head off before something major.. and it is a hydro head with new lifters.. I think it may be a precup also.. anyone else have a precup rattle when cold..

[kevinm]

My oil is 15/40 diesel grade no name crap.. I've heard from a friend its the way to go for break in..

[Gizmoman]

If they were "a little cracked", I'd defiantly pull the head. When they are in good shape (no cracks but loose) it's tough for them to drop out as they are held in somewhat by the deck of the block (not sayin' it can't happen though). If they are cracked and moving around, a chunk could drop into the barrel and ruin your day.
Again, I'm no expert here. The only other possibility would be a sticky lifter if you have already ruled out the injectors. Everything is affected by heat.

[TylerDurden]

Now I'm getting paranoid.

My 89 1.6 NA has an occasional knock/tap sound from the intake that gets quiet after running a few minutes (even happens when the engine is warm).  I have been telling myself it's just a lifter that is filling slowly or a bit sticky.

The tone sounds like tapping on the filter-box with a plastic mallet. Very audible, not subtle.

I have never been into the engine, it runs very well and gets 45/50 mpg.

[Gizmoman]

Don't mean to worry you and as I said, I am no expert on these engines.

I'm in the middle of a rebuild myself because I worked the thing too hard with no EGT sensor/gauge and cooked #4 piston. I had a slight ticking noise from a previous "hard" trip (it's in a heavy camper van and I was climbing a lot of grades in the Sierras in the summer heat). The ticking was only there when I gave it fuel (load), when I took my foot off the pedal, it would subside (no load). My first thought was injectors so I did the "loosen the feed lines one at a time" test - nothing seemed to change. I still went through all the injectors, built a pop tester, etc - no change.

When I finally pulled the engine and removed the head, I found #2 pre-cup loose enough to take out by sticking a screwdriver in the hole and simply pulling on it. As I understand it, they are pressed in and should not be loose at all. I believe this was causing the ticking sound.
Just to be clear, the ticking I had was worse when it was cold but it never totally went away after it warmed up. However, it did get a bit quieter (or I just got used to it).

A quick search on here will lead you to a lot of info about loose pre-cups. I believe Theman53 has some excellent posts regarding this specifically and I took his advice seriously (I bought a new head). All four of my pre-cups have no "cracks" in them, just one was loose. When you said yours did have cracks, that made it sound pretty scary as there's not much to them and they do a HUGE amount of work. Maybe you meant loose, not actually cracked. If you meant cracked like almost into small pieces, I'd pull the head.
Here's a shot of the pre-cups - not much to them, hard as hammered cat turds.