So was on the freeway one day going to a friends house and then all of a sudden the power of the cars goes to nothing and my oil light flashes on and off. i immediately pull of the road on to a seperate road and check everything took off the valve cover to look at everything up top. everything looks fine so then i take it in to the dealership and they called me to find this...


Would anyone know what could be the cause of a lnf oil pump to break like this? i cant find out what it could be. oil i run in the car is mobil 1 synthetic 5w 30

Thanks guys!

 

just curious as to what crank pulley you had on the car? stock or aftermarket?

 

it was a aftermarket one, however ive had it on the car for the past 20k miles and theres never been a problem. im just confused on this part.

 

damn ryan! u killed that thing lol hope u get it fixed under warranty!

 

thats the thing i was doing 70 mph cruising on the freeway

 

has anyone heard of anything like this?

 

Cheap aftermarket pulleys tend to lead to this. It's why even professional race teams don't run undamped pulleys.

Bet there isn't a single shattered gear on a stock pulley. If they warranty it, you're lucky, because it shouldn't be.

 

not looking for warranty just to find the problem and fix it i have too many mods on my car. but thanks for the input. im pretty sure there are people that are running on big turbos on this stock pump.

and also is the gm ecotec racing pump the one that comes in the lnf? because they look identical.

 

ive heard about possibilites of damaging the timing chain, but never this. Ill be putting my stock pulley back on tommorow if the rain stops. damn dude. sucks this happened but i hope you get the car back quick

 

Big turbo or not, it should not have any effect on the oil pump. It doesn't have anything to do with power level, only rpm level. The reason it blew is because of the aftermarket pulley and not having the engine harmonics dampened.

The GM billet racing one looks identical in size and shape because it is. The difference is only in the composition of the metal. But I do not believe the LNF got the GM racing one as stock.

Billet is going to be a lot stronger than the stock piece, but I still wouldn't run an aftermarket undampened pulley on it. Get an ATI SuperDamper or something similar, or go back to stock.

 

ya im not sure if there is a difference as far as the pump gears between stock and the race one and which one already came in the motor. but if there is a stronger one i will put it in might as well since im building back up the bottom end of the motor. and ill more than likely go ahead and put the stock pulley back on just for reassuring purposes. and ya it sucks. i know all ecotec has a gm racing pump gear that looks exactly the same but its like $365 which is pretty pricey. anyone else know of this problem? ive never heard of this happening. and ya hp shouldnt matter as far as a oil pump breaking if anything i would think just rpm and oil.

 

Possibly unbalanced part spinning around at high speeds. Yeah something was gonna break at some point.

 

Def the aftermarket pulley caused that. Remember, the pulley sits right in the oil pump drive, so any extra vibrations will cause that gear to stress and eventually break.

You could try a GMPP hardened gear, but the best option is a real aftermarket pulley or the stock one to prevent future problems.

 

not sure if the LNF has the same oil pump gears as the lsj but if it does I have them for sale
https://www.cobaltss.net/forums/part...s-sale-260942/

 

so the gmpp hardened gear is like a billet piece? and ya im prolly just gonna go back to the stock one im not sure where a aftermarket one thats gonna work would be sold at. unless gm makes one of those too. Im surprised if thats the cause that it would have lasted around 20k miles until something happened... but then again the stock oil pump gear should be good as long as its mated up to the stock crank pulley?

 

you can buy the hardened pump gears at allecotec.com ...i got them and they are stock gears hardened. So if you don’t mind spending the extra money and plan on modifying your car a lot they are worth it

 

No reason to run the hardened gears unless you're running the car in road-racing conditions, extended periods on the rev-limiter or at very high rpms.

 

Agreed. These are overkill for 99.99% of forum members. Nice part to have, but not really needed unless road racing.

 

ATI is the only way to go

 

thanks for all the info guys im getting the car back today and i guess ill just get the stock gear seeing how the highest rpm i plan to hit ever is about 7700 and i dont road race lol. drag strip every once in a while. i think the stock gear pump is only sold in a oil pump assembly kit as well i believe

 

like I said if those are the same oil pump gears as the LSJ I have them... make me an offer and there yours if your interested!

 

thanks bro ill look into it and let ya know

 

Wasn't there a thread with a bunch of people claiming that the un-dampened crank pulley wouldn't have any negative side effects for 11,000,000 miles or something?

Edit: Yeah, he it was:
https://www.cobaltss.net/forums/2-0l...y-well-234621/

Is this what is being claimed as the probable culprit in this pump failure?

 

in for answer to above post

 

MRZ or MPX ?