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Engine noise

Posted: Sun Sep 03, 2006 11:51 pm
by capecodberetta
Hi ALL..............

I have a 1990 quad 4 2.3L engine.
It runs great, but the engine has a ticking sound. It is similar to a "stuck rod" sound.
This is my first quad 4. Are they quiet when running, or not?
Thanks,
capecodberetta

Engine noise

Posted: Mon Sep 04, 2006 2:03 am
by docrodg
Could be many things.  Try to lcoate the noise as to top or bottom, left or right.  Take a screwdriver and place it on the rocker cover over each valve pair and listen.  Chances are it is a lifter that is stuck and you will hear the valve clicking as the extra lash is taken up.  Also check the accessory belts and alternator etc. For the noise, but first bet is it's a lifter.

Engine noise

Posted: Mon Sep 04, 2006 12:19 pm
by rjc333
Yeah, I once had the same ticking noise with my old Quad.  Mine ended up being a lifter.  If I stand correct, Quad's use a 'roller-type' which are more expensive than the normal ones.  Like Doc said, it's more than likely a lifter.

Engine noise

Posted: Mon Sep 04, 2006 9:43 pm
by capecodberetta
Thank you very much for your input.
capecoberetta

Engine noise

Posted: Tue Sep 05, 2006 8:09 am
by rweatherford
Quad's use a flat hydraulic tappet lifter.  No rollers.  They are like an upside down bucket that sits on top of the valve spring.

Engine noise

Posted: Fri Sep 08, 2006 10:12 am
by rjc333
(rweatherford @ Sep. 05 2006,07:09)Q
U
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T
EQuad's use a flat hydraulic tappet lifter.  No rollers.  They are like an upside down bucket that sits on top of the valve spring.
My bad.  I got them backwards then....

Engine noise

Posted: Fri Sep 08, 2006 2:20 pm
by blindmandesigns
Here are the lifters for reference from my W41 cams. (still haven't put them in yet...


Engine noise

Posted: Fri Sep 08, 2006 6:22 pm
by Guest
Quick question related to this thread, what parts of the valvetrain can you replace while only having to remove the rocker covers? Can you do the lifters? Because the front cover on my 3.1 has a lot of ticking coming from it.

Engine noise

Posted: Fri Sep 08, 2006 11:57 pm
by docrodg
You can do the lifters without yanking the engine on almost all chevy engines.  On V-6 and V-8 engines you can can do it with removal of the intake manifold in most cases, some rare engines do not require the intake be removed.  Those lifters look pretty galled on top, not a good sign.

All chevy production engines except special HO engines are hydraulic lifters and they can fail if they get gunked up or break internally.  There is a leak down test but normal shade tree folks don't have the arbor press needed.  Try an engine flush, or as the heads are removed clean them with a nice long soak in cleaner and a good drying.  Then prefill them by placing in a pot of oil and heating them up then letting them cool off, the oil will be drawn in.  If that fails then try loosening the rockers with engine running one at a time and letting the lifter pump up, sometimes an easier method .  Then retighten to spec and should be fine.  If that doesn't fix it then you may need to replace the lifter.  Can't really tell in the pic but seems the left lifter shown is cocked in the top, indicating it may be jammed.  

Keep them in order if you remove them.  Otherwise you can ruin the cam.  Also check the cam and make sure it is good, often you can get a cam and lifter kit for little more than the lifters themselves.  The bearings are likely ok, as chevy has designed the cam to wear before the bearings if properly maintained.  This is due the horror in replacing the cam bearings (engine removal).  Nice engineering trivia on Chevy.

Engine noise

Posted: Mon Sep 11, 2006 11:20 pm
by rweatherford
Docrodg,

I can tell you are very knowledgeable, but the Quad is a different beast.  Those are the bottom of the quad lifters and they touch directly on the valve stem.  They are probably fine and there is nothing unusual about them.  The Quad also has no cam bearings and the steel camshaft sits into an aluminum housing.  The camshaft housings have to be removed to change lifters and if you are not swapping cams then you should leave the housings in one piece and not disturb them.  Then you must be VERY careful to not overtighten the camtower bolts and strip the aluminum threads in the head.