sounds like rod knocking.,.need advice
 

Hi guys...I've already done a search with no avail.

Here goes, 93 sc300 150K, when I cold start my engine I hear a loud grrr for abt 3 secs, goes away after that. then I restart and hear no sound..Also I hear a ping like sound when I accel..sounds like going up in a roller coaster.
Everything else sounds normal, when running when parked sounds smooth.

Been told by 4 mechanacs it's the main rod and I need a new engine. Put 5W50 in it and get rid of it.

I took to my old mechanic and he stated I need a complete tune-up. The start up sound is the abs braking system?????

I tend to believe it's the rod..
Need help Thanks :confused:

My buddies MR developed a rod knock but you couldnt hear it at idle. Open your hood and slowly raise the rpms and listen to see if through the rpms the knock gets louder. Also when you change your oil check to see if there is any metal flakes in the oil.

Sure sounds like a rod... sometimes after sitting, you may hear a knocking just after startup, then when oil pressure gets up, the knocking temporarily goes away. Usually I find that the knocking will be most pronounced under engine load

Rod and Main brg knocks.
 

The knock at start up is your first indication a bearing is going south. Eventually it will knock at all times. The problem with letting it go that far is that you get enough wear that the crank needs turned at least 20thousandths. The up side is that you don't launch into major expense without being absolutely sure. Have your oil ANALYZED and you will know for sure as it will have bearing metal in suspension. Oil analysis is rudimentary to good engine maint and an ongoing analysis of how good a job your brand of oil and your change ibtervals are doing. Peace of mind and validation of the oil manufacturer's claims. Had you had your oil analyzed a couple of times a year you would have seen this coming and been waiting for it to happen or would have changed somthing to prevent it.

It would seem that you have verified the problem with numerous "expert" opinions. You have a bad main bearing. Why is the question. Poor maint means you have bad main bearingS. The slimest of chances is that you have a single over clearenced bearing and could recover the engine by only changing out the defective item. Slimest! If you are in there you would certainly replace all the bearings, especially as they are sold as SETS. To inspect them you need to remove the pan, take off a main cap, exert force on the crank in the upward direction and use plastigauge to determine oil clearance. "Remove the pan" was the operative word here as that may be impossible with the engine in the car.

Rod bearings and wrist pins will knock when you briefly rev the engine. They also knock when you let off the gas.

You have said that you get KNOCK (grrr in your words) when you put load on the engine. That is the test...if it knocks under load, it IS mains.

I think a used engine is, by far, cheaper than rebuilding the engine. The engine "should" go 300K miles but you are having a different experience. So...? You need another expert and I still am not one. Especially one with Lex specific history. Start a dialog with Gazi Ali. He can give you tech advice and, perhaps more importantly, a used engine that you could have a measure of confidence in. You can get a used engine for less than a full gasket set would cost to do a rebuild....I think. Talk to Gazi. Get that oil analyzed.

Ping is a very tinny sharp sound that you shouldn't confuse with a bearing. Any mech would exclude it easily.

I'm not the last word here and you should make an effort to verify anything you are told. That you went to numerous shops speaks highly of your caution.

Hope this helps. Good luck. Let the board know how you made out.

JohnEd

Thank you all for your excellent advise ..I'll be getting the car checked out completely in the next couple of weeks and will let you know my decision.

Hi again..

I made a descision to put in a new engine..I received a price w/ labor of $1600 from a good mechanic, with a one year warrrenty on the engine.
My next question is ..I see here on the forums abt swapping engines.
Can you guys please give me more info on the positive of going with the other engines..Thanks for your inputs

By swapping engines I am guessing you mean for going FI right>? If you are wanting to run boost then yes, that is what our should do. If you just want a normal, RELIABLE SC300 then stick with the 2jz-ge.

Jonny