Hi All,

I'm new to the forums, there is an amazing wealth of information on here, I did some searching but couldn't quite find the answers to my problem.

I bought an 01 996TT about 2 months ago, it's a stunning car, 48K Miles, has a few of the standard issues, slave/accumulator need changed, coolant overflow tank leak, and the knocking noise at idle I've seen people complain of. I'm gonna take my time and use some of the awesome posts here to get me confident enough to DIY the first two.

I'm really mostly worried about the knocking, the guys at Cantrell in Kirkland told me it's common but is definitely louder than in most other cars they've seen. They believe it's the oil pump. It doesn't happen when the car is cold, only when at normal operating temp, and only between about 1k-2k rpm, just above idle, above that it seems to go away. It is loud enough to hear from within the cabin even with the loud exhaust, sounds pretty bad from the outside. I've seen a few threads about engine failure related to oil pumps dieing and I don't want to end up starting another one!

Is a noisy pump actually more likely to fail than a quiet one? (my gut says YES...) How much should I expect to pay to replace it? I assume it involves completely removing the engine, I couldn't find any good posts about replacing it.

I can handle dropping the engine a few inches (It would probably also help with the coolant overflow tank change and EVOMS GT2 slave delete), If that'd let me get at it I'd be game to try, but major engine surgery is well beyond me!

 

Hope it isn't pump.... or a bad bearing/rod/piston slap/intermediate shaft that's thumping.

Hope it is..... Lightweight flywheel perhaps ?

 

Oil pump R and R is a complete disassembly of the engine. These engines sound like they have a bag of marbles in them on a good day. I would let a good engine builder take a look at it.... Alex at Max RPM or Kevin at UMW would be a good start, both are in Washington. Good luck.

 

I don't believe it has a LWFW, havn't heard any of the tell tale chatter, but can't be sure, i do know that Clutch in/out doesn't change the noise at all...

 

Not a bad idea, I should definitely take it by and get a second opinion of the noise.

 

KPG is right... get used to it sounding like a bunch of rocks shaking around in a can... there are a ton of post covering this... u really dont want to rr an oil pump if not necessary its in the worst possible spot everything has to come apart even split the case etc and u will be pissed when you start it up afterwards and it sounds the same LOL ... if you have money to burn($8K or so just for labor gaskets another $1200) be sure to pu aftermarket rods, studs and fuel injectors and let the fun begin ... o yeah if you do aftermarket head studs you will have to heat cycle the motor and re-torque the studs so the heads wont lift off at WOT (i speak from experience)
tim

 

LWFW will definitely make rocks in can noise...

From what I know, you do not want the oil pump to fail as it will damage other internal components..

 

LOL, true, sounds like I'd practically have to have the engine rebuilt just to fix a rattle.... I'll swing by Kevin@UMW and get his opinion on it. Thanks for the advice guys.

 

Let us know what Kevin says.

I'd pull the oil filter during the next oil change and look for metal particles. Then maybe do a oil analysis to see if there's any excess amount of metals in the oil- which could mean bearings.

To be honest- I bet it's nothing- these motors make a lot of noise... If it goes away off idle, I've been told to not worry about it.

 

I changed the oil 2 weeks back, the filter/oil didn't have any visual warning signs, I didn't do an oil analysis though, that might be something to try next change.

I'll post back with Kevin's feedback.

 

thats because there is nothing wrong... take a look at usp motorsports thread it seems that chris green has proven the gt1 motor is indestructible LOl... i have been active on this forum for a few years i cant recall ever hearing of an oil pump going out... i guess we will wait and see... or maybe drive it like you stole it and give the oil pump a work out

t

 

There was one post here I remember where there was an excessive amount of noise that didn't go away when the motor was revved above idle. Turned out it was the IMS bearing.

That being said, I think an issue like that is VERY rare with the GT1 motor... I wouldn't sweat it- is your oil pressure OK?

 

Was it jhaung's oil pump that failed or something else - going from memory...

 

Yeah the oil pressure seems just fine, bit over 2 at idle, and rises steadily to 4.5 at ~2k rpm and holds there. Chances are it's just fine, i'm probably being paranoid!

 

Some cars are noisier than others. My buddy's 02 is much louder than my 01. IMS shaft problems are mostly related to naturally aspirated 996's not turbos. I've completely rebuilt my engine and believe me you don't want to go there unless your forced to.