clicking from engine... "shouldn't" be valve gaps

[ret]

Well, to add to my SHO troubles, the engine is making a sorta clicking sound. It sounds like a stuck lifter, but I just ran some engine flush through and changed the oil and it's still doing it, so it's apparently not that. The next most obvious thing would be valve gap, but the engine, including the heads, only has about 25k miles on it, so it "shouldn't" be needing this allready. The sound can only really be heard outside the car with the hood up. It sounds to be coming from near the center-top of the engine, like near the fuel rails. Is it probably the valve gap? Any estimates on what it would cost to have just the valve gap done and not the rest of the 60k? I really can't afford to have that done if that's not what is needed, especially since I assume it would take more than one day, so I would have to take 1 or 2 days off work.

 

[luigisho]

Why would you need a valve gap if the heads only have 25k on them? I think there is a light ticking noise that is actually normal with these engines. I think I saw a post regarding this while someone was at Sho Nut talking to Josh T.

 

[jthomas68]

The injectors make a "tick" sound when they fire.

 

[ret]

That's my thought, too, it shouldn't be valve gap issues. That's why I first thought it was a sticky lifter, then asked here to see if anyone else has any ideas. As long as people are sure nothing is being damaged, I can live with it, but if something is broke, I need to fix it, especially something serious like that.

edit: ok, cool, injectors ticking would make sense with what is going on. speeds up when more throttle is given, sounds to be coming from that general area, etc.

<small>[ April 16, 2002, 09:11 PM: Message edited by: ret ]</small>

 

[sdpatt]

The SHO engine does not have lifters. It has inverted bucket tappets. There is an upside down metal bucket covering the valve stem and spring. On top of this bucket is the shim which is approximately 2.5mm thick. The cam lobe directly contacts this shim. There are no shock absorbing hydraulic lifters or roller rockers to add weight or sound absorbers to the high-revving motorcycle-like valve train.

With the engine running, take the oil fill cap off and listen for a change in the volume of the tick. If you can hear the tick coming from the oil fill hole, one of the front bank cam lobes/shims/tappets is making the noise. This can't be done for the rear bank, but you can place a screw driver tip on the valve cover and press your ear to the handle of it to listen for the source of the tap.

If either bank is the source of the noise, it would necessitate the removal of the intake and valve covers to perform the inspection of the condition of the valve shims and the measurement of the gaps between the cam lobe heels and the shims.

The introduction of any engine flush could only cause more lubrication difficulties in the SHO valve train. Please don't do that again.

Just how loud is the tick? A large gap, even still in the allowed range, could possibly make a noise that may alarm you, but not actually be an immediate hazard to the health of the engine. If the noise gets louder rather than softer, it may indicate the need to have the valves gapped. Just because the heads came with an engine, there was no guarantee that the valves had actually been gapped as during the 60K adjustment. Just curious, what brand of oil are you using?

 

[ret]

The tick isn't very loud, with the hood shut you can't hear it at all. With the hood open, I still have to listen for it (well, not as much since I know it's there now, but before I was sure I had to listen for it) or put my head closer to the engine.

I've taken the oil cap off and listened, definitely not on the front, I'll check the rear after work today.

As far as oil, I am now using Castrol GTX. I had been having it done at Jiffy **** (my jack, jackstands, wrenches, etc are all back in Iowa at my parents, so I just bought new ones to do the change myself), I think they use Valvoline or Pennzoil.

Thanks for pointing out not to use engine flush in this engine. I usually like to use engine flush 1/year or so, so I'll remember to not do it with this car.

 

[sdpatt]

If you use Castrol GTX you don't need to use an engine flush. Use Pennzoil and there is no engine flush strong enough to clean all of its crap out of the engine.

Scott

 

[ret]

That's exactly why I started doing my own changes again. I saw no point in paying jiffy **** $30 to use crap oil when I can do it myself with good oil and a better filter for $15 or less.