Tell me its nothing...PLEASE

[coach]

Hey guys,
I could swear that after my car sits for a few hours and I start it up, I hear a little knocking until the oil pressure comes up. What gives??? If it has been doing it for a while, I never noticed because I was running an open dump. Now it is capped off and I have paid more attention. I also added boost over the last week and have,well, beat it up a little. No knock or bad readings, just normal street abuse. My issue is , I am going to race it this weekend for the first time EVER. I am going to change the oil before I go. What weight oil do most run? This motor has 20,000 miles on it, but I want it protected and do not want a lighter oil than most are running. Any help is greatly listened to.

Thanks as always,
Coach

 

[Squid4life]

First off, don't race it until you figure it out. Maybe a lifter went south? How bad is it? Rods and mains sound different than lifters/rockers. Buy one of those cheap plastic stethiscopes (sp?) and listen around to the valve covers, cam sensor, front cover, pan, block, etc. Good luck.

 

[mtocrs1]

I would put 20W50 Valvoline racing oil in it and give her hell. If something is wrong you will know.

 

[Squid4life]

No offense, but thick oil will only mask the issue if there is one. With only 20k, 10w30 should be fine. Check it out before putting any load on it, unless you just want to break it and rebuild.

 

[bison]

A higher viscosity oil will not affer more protection and may aggravate a cold start knock problem since it flows much slower than a low viscosity oil when its cold. I run 15-40 with 4.5-5 quarts in the pan. 4.5-5 quarts is all i ever ran and all thats needed imo unless you have an engine with drain back problems. I never drive it hard till the oil is hot.

 

[coach]

Like I said, I can hear it for just 3-4 knocks then it s gone. I know it is oil related. I just never dreamed I would hear it with only 20k on this motor. This motor sat for years and I have run the crap out of it for 2 1/2 summers now. It runs awesome. I think I will go with 10-40 and some ZMAX additive along with my ZDDP. I had an old slant 6 mopar that did the same thing for years and you could not blow that car up if you tried. I hope a Buick is as tough. Could this be an oil pump problem?

Coach

 

[TR Custom Parts]

Bad anti drainback valve in the oil filter???

 

[Twistin6]

Like mentioned earlier possible bad drain back. With the heavier oil you may be hearing the lifters as they pump back up which evidently is quick with only 3 or 4 knocks so oil pressure is probably good.

 

[coach]

Doesn't sound like lifters. Sound is much deeper like lower end. I do not want it to be , but it sounds like it. WS6 is coming over this morning to listen to it. He says his TTA has always had start up noises and knocks. We'll get 2 opinions and repost.

Thanks to all, and I will be in touch,
Coach

Keep your fingers crossed!!!

 

[Grumpy]

shot in the dark ..converter bolts... oh my TTA brand new would make noise on start up . BUT the car ran to good to take it back under warranty so we just drove it like that for 90k

 

[Nasty]

Knock or tap during a cold startup I would think is either oil related, mechanical, or remotely possible (though doubtful) excess carbon in the cumbustion chamber.

Oil related on a stock 20k mile engine in good condition should be resolved with a good filter and good 10w30 oil. If it is still there, then its not the oil, unless the engine as been rebuilt to a different spec, then it may need different oil (20w50 in my case). Don't skimp on the filter, the drain back feature is important. Wicks/NAPA Gold would be good choices. You can try 5w30 (flows better cold). Being your engine does not make noise warm, I doubt that a heavier oil will help-but you can try 20w50. 10w40 probally will not make a difference over 10w30 if you have a knock noise cold, but again you can try. If you go through switching oils, I would not bother changing the oil filter each time as its not cost effective and you would only be checking the engine cold 1 or 2 times to determine if the noise is gone or not.

If you go through all of that and its still there, you could consider the carboned combustion chamber thing as its cheap to clean it. I have heard cars with excess build up and it sounds just like lower end knock-goes away after a few seconds to a minute (varies). Chrysler Combusion Chamber cleaner in the aersol can works good, not sure if it would have any adverse effects on the turbine exhaust seals of the turbo as it exits-but I would doubt it. Its a cheap attempt, and of course we all could benefit from a cleaner combustion chamber.

if it is mechanical, and you are SURE it is not a lifter, then I would say bearing wear. That may get masked by the heavier oil, and heavier oil is not a fix as the wear will get worse.

Also, like Grumpy said-check the converter bolts for torque and any signs of rubbing contact.

Oh, BTW the slant 6 Dodge engine is a hard one to kill-I bet you could run it on veg oil or the like-lol.


Good luck, and keep us posted.

 

[TurboV]

How does the oil pressure look? Do you have a Gage? To answer your question in you original post, I have been running Royal Purple 10w-30 with ZDDP additive for over a year now and never looked back. Keep us posted.

 

[TurboV]

Oh..... And ive been using the Mobil 1 extended performance oil fllters. (The larger size...M201 i believe.)

 

[novaderrik]

could be piston related- if you know anyone with a Chevy truck from the early 2000's, ask them to start it up cold and see if the noise is the same. 90% of them have a slight knock for the first few seconds of run time that is harmless but soundsl iek crap.
also, motors with forged pistons that have looser clearances will do this, as well.

 

[GNeric]

This would be my first check. Cheapest to just get a good filter and try it. Use the old "suck/blow" test to see if the valve closes before you buy it.

Bad anti drainback valve in the oil filter???

 

[Turbo1dr]

Hey guys,
I could swear that after my car sits for a few hours and I start it up, I hear a little knocking until the oil pressure comes up. What gives??? If it has been doing it for a while, I never noticed because I was running an open dump. Now it is capped off and I have paid more attention. I also added boost over the last week and have,well, beat it up a little. No knock or bad readings, just normal street abuse. My issue is , I am going to race it this weekend for the first time EVER. I am going to change the oil before I go. What weight oil do most run? This motor has 20,000 miles on it, but I want it protected and do not want a lighter oil than most are running. Any help is greatly listened to.

Thanks as always,
Coach

Not to be the bearer of bad news but during the life of that 20,000 mile GN and the performance parts that's installed...I would think that almost every time that car gets driven... it's driven hard. What I mean by hard is "foot on the floor" at least once during it's many short trips (as indicated by having only 20,000 mile on it). I think it's about time for some bearings before you spin one.

 

[coach]

Well WS6 came over and listened to it. It never made a peep. Sat all night and I figured if it is going to due it on dry start, over night is as bad as it gets. He listened with his engine stethoscope and nothing. Went for a ride and it runs totally awesome. A 4 pound launch spun the MT Drag radials for about 10 feet and it was on. I will double check everything before I hit the track next weekend. Oil change and ZDDP, check convertor bolts, etc. I will keep you guys up to date if anything turns south.

Thanks as always,
Coach

 

[turboclam]

I'm with the other guys. I would try a different oil filter. What filter are you running and how quick does oil pressure climb on start-up?

 

[coach]

Don't have an oil pressure gauge. Just boost, fuel pressure, and tranny temp gauges are in the car. Oil pressure is on the list, but I have not put one in. I will try the Mobil1 filter. I believe the one I have is a large Hastings. WS6 and I are going to cut open the old filter and inspect it. I will post.

Coach

 

[GNVYUS 1]

Sounds like the same thing I went through about a month after I bought my second GN with like 52k on it. It had developed a rod knock from the douche before me not owning an aftermarket boost gauge and it hitting 18psi at WOT and knocking like hell.

It would knock for about 3 seconds at start up until oil hit the rod bearings, even worse when I did an oil change, about 5 seconds of rod knocking.

I got a Preluber to prolong it's life as far as I could but after a couple of months I just pulled it.

Thinner oil has a lower start up viscosity so it will hit the bearings faster, thicker oil is better after that point but it's most likely too late.