Squirrels under my hood

[AnytownUSA]

My valves are chattering under somewhat light acceleration. It started yesterday. Now I tend to shift earlier than most people, keeping the RPM's under 2k most of the time (highway driving). I have not really hit the throttle hard since I noticed the clicking (mainly because I didn't want to mess anything up) so I am not sure if it happens under hard acceleration or not. What has caused this and how can I fix it? It just started so I would not expect it to have done any damage - yet. Could it have hurt anything yet?

Speaking of problems, my oil plug it dripping. Last time I changed the oil I put a new gasket on it but it still drips. Is it supposed to be torqued to something specific? It isn't much, it doesn't leave spots at work but it does in the garage at home. Any suggestions on how to prevent this? I thought simply replacing the gasket would do it but apparently not.

Thanks for the help, I know I need to find some shop manuals but I checked the Helm site but they don't list service manuals for a 1994 anymore, what gives? Oh well, I guess I'll have to fight for one on Ebay.

 

[Vettelt193]

are you sure it is the valves? the injectors make clicking sounds, and so do roller rockers if you have them... is it just a case of you not hearing them before, or are you sure something is wrong?

 

[AnytownUSA]

I am 90% certain the noise is new. I have heard other fuel injectors firing, but this clicking is much more metallic than what I remember hearing in those injectors. But, I don't know what these injectors should sound like so... Also, I have not been able to get it make noise after it gets good and warm. Maybe I should have done some more investigation before I posted. I don't know if I have rollers or not, everything is stock so I assumed they were hydraulic lifters. I had this happen on a Camaro several years ago, a guy at Pep Boys told me to put some Slick 50 in and it still made noise and smoked everytime I started it until a sold it. I'll pay closer attention this afternoon and keep in mind that the injectors and possibly rollers could be the cause. Any other suggestions that I should listen for? Or anyway that I can know if it is the lifter or not. I guess I could get a stethoscope (spelling?) and listen to the valves that way.

 

[Vettelt193]

The injectors click, but they don't make a ton of noise... many put Roller rockers in aftermarket, but if yours is stock it won't have them... you can easily tell by just opening up the oil fill cap, if they are gold or silver you have rollers, otherwise they are stock....

Since you are pretty sure it is a new noise, can you tell if it is coming from a specific side? I would not suggest using slick 50, it does not work and clogs your oil filter.

How many miles do you have on your car? do you still use Mobil 1? what weight oil? when was your last change?

 

[AnytownUSA]

Vettelt193,
I was mentioning the Slick 50 because the guy I could put that in the crankcase and it would fix the lifters, but all it did was cause other problems. I will never use anything like that again. I will pay closer attention this afternoon and see if I can tell from what area where the clicking is coming. I use Mobil 1 5w30, the car has 53k miles. I asked on the boards when I first got it when to change the oil and several folks said doing when the Oil Life Monitor came on was fine. So I have only changed it once since I got it in January. But, they have been doing some construction on my way home so I may have picked up some dust that the monitor is not supposed to account for. I'll change the oil this week and see if that helps. I will double check for rollers when I leave work - he told me it was all stock, I know he bought it new but you never know for sure about customizing. I appreciate your help with this. I should have gotten my ducks in a row before I posted but until you started asking questions I didn't know what info was required. Thanks!

 

[evolution]

I thought you meant...

 

[Vettelt193]

if you knew what to look for, you wouldn't have needed to post to start off with... questions back and forth is the best way to fix don't worry about a thing....

The oil life monitor, In my opinion, is BS. I think it just comes on every 7500 miles. I like to change every 3000, because I don't drive my car much... it sounds like you don't drive yours every day either, considering the low miles? If not, stick with 3000 miles, it is cheap insurance... this may be a really stupid question, but have you checked to make sure the oil is full?

 

[AnytownUSA]

Evolution: Those may the little boogers right there, but they move so fast that I can't the hood open to catch them at work!

Vette: I do drive it every day. I bought the car in January with 42K on it. I am not supposed to be driving it every day though. The agreement with my wife was that I could get the vette if I kept driving my little Mercury convertible - after I changed the alternator and coil... For some reason I have not gotten around to that yet! Virtually 85% of my driving is highway so I could stretch the oil a little anyway, but as the monitor hasn't come on a second time I can't tell if it is recorrent at 7500 or not. I fear I will be forced to fix the vert' and use it every day after this X-mas. But wait...it still needs a new top - that could buy me at least 4 months! I am contemplating having the vette's heads done, and maybe installing some rollers but I have not yet weighed the goods and bads of each. I also have to find a good flowing exhaust with cats.
the oil is close enough to be full, but I'll top it off tonight. You think low oil would make the lifters click - that is assuming it is the lifters which we have not yet determined.
I will gather more information and post it tomorrow.

 

[Zektor]

Mmmm! Interesting problem...

You say you only hear this problem when the engine is cold... yes? If so, a lot of hydraulic lifters in quite a few cars may make a tapping noise for up to about 3 minutes or so when starting the car from cold. Only when the lifters are pressurised with oil will the tapping noise go away. If so, then I shouldn't worry to much, it's quite common with hydraulic lifter equipped vehicles.

Now that your car is approaching 60K miles valvetrain wear, not detrimental wear, just normal wear is evident in most cars. Your hydraulic lifters could be compensating for normal "wear" in your valvetrain.

A couple of things you could do is to take your valve covers off and adjust all of your standard rockers down to zero lash (like when new) again. Or replace all your pushrods and rockers for Roller Rockers.

Other things to think about are... failed lifters. A lifter may be blocked or just plain worn out... therefore not pressurising properly and making a lot of noise.

Or is your car possibly pinking on startup? Normally pinking is heard whether cold or warm. But maybe something is wrong with your car on cold start/warm up.

Just a few idea's... good luck!

Cheers
Dazza

 

[AnytownUSA]

Okay Zektor, what is pinking so I can listen/look for it? I would like a reason to get into the valves, maybe I'll lash them just in case.

What would a failed lifter sound like? Does it casue any other problems that I could cross check?

 

[Black Ice]

I have a tapping sound on acceleration when my motor is cold. I dont hear it much at all at idle. Once the water temp reaches 160 or above its gone. I have a 96 with 30k mikes. I was also told it could be small carbon marbles in the piston chamber causing the sound and to have a top engine cleaner treatment.

 

[AnytownUSA]

My ticking may be temperature related. I did not hear it yesterday afternoon or this morning, which was warmer than the previous two. So no more info as of yet. I will post when it does it again to refresh the post.

Black Ice: Mine does not make noise after it warms up either - that I've noticed. What type of top end engine cleaner did he recommend?

 

[3TT3V]

oil plug dripping....try a couple wraps of teflon tape on it the next time you change oil.

 

[Black Ice]

GM has some goo the dealer floods the engine with through the fuel line. You have to leave it soak for a couple of hours then they drive it and it smokes like crazy for a while. Its made to purge injectors and dissolve and soften carbon buildup so it can be burned away.

 

[JRMaroon]

Does this have any effect on the cats? Plugging etc?

 

[Black Ice]

I dont think so Chevrolet did it to my Blazer under warranty. Its a GM product. It did help a lot. Its called "Top Engine Cleaner"

 

[AnytownUSA]

3TT3V: Teflon tape is a great idea. I don't know why I hadn't thought about it earlier.

Balck Ice: I'll check on the cleaner process, it couldn't hurt with 53k miles.

 

[3TT3V]

I would recommend not getting sloppy with the teflon tape. A minimum amount should suffice and wrap it onto the plug so that none of it is exposed into the oil pan.

 

[AnytownUSA]

Will the tape melt at temperature? Along that line, if I use the tape will that eliminate the need for the gasket?. It seems it would but I cannot remember of the plug has threads all the way up or if they stop where the gasket should be to prevent cutting into the gasket.

 

[3TT3V]

yes ...use gasket.
no...the teflon tape will not melt.