GSpence2

My bet is wheel bearings

Had the same problem and ordered my kit from Vertext Automotive 

Completed the repair in about an hour for about half of what you were quoted

I had a similar problem with my 996TT after swapping bulbs. Turned out I broke the lamp housing when fitting the socket. The socket went back into the bayonet like mount but wasn't making good contact. Ended up replacing the housing with a used one.

My CTT sounded just like this right before an expensive rebuild. https://www.renntech.org/forums/topic/50695-on-the-eve-before-christmas-the-gremlins-gave-to-me/#comment-283614

You're welcomed. Good luck!

I recently had a round of random crazy codes like this that all pointed to a voltage issue but it wasn't the battery. Turned out there was a power cable next to the driver's side SAI pump that had made contact with the pump and the chassis. The insulation had worn down causing a big short and random codes until the power cut out altogether. Replaced the cable and all is well again.

Yes as always Mr. Weller is spot on! So far the tranny and transfer caseand diffs have held up well without issue. Tiptronic was always sloppy anyway but I think that has more to do with the software and valve body than the robustness of the basic ZF unit. And yes,Trump is an idiot and Putin's puppet!

I recently completed a rebuild on my 04 CTT after burning up 2 cylinders. I figured in for a penny in for a pound (more like $12K), and went full hog, or porker in this case. The rebuild kit resulted in an over-bored block with bigger pistons. While we were in there we swapped out the intercoolers for CTT S types. We found the right front cat had rotted out so changed the exhaust to a high flow sport exhaust and bypassed the rear cats. The truck already had a cold air intake system so just retuned everything with a custom flash. The throttle response is instant now, lag is nearly 0. The boost comes on hard from 2000 RPM and below that with PSM turned off. Haven't dynoed it yet, but running side by side with my partner in my 996TT, it's a dead heat. Worst part is 500 miles later the right rear half shaft gave up, then the left front at 1000 miles. Big power means upgraded driveline. Next up, driveshaft from Lindsey Racing and some bigger brakes!

Ha! Vroom vroom boom! I love it!

Thanks Mr H!

What is it and what does it do? 2004CTT

PPI, mechanical inspection, pull the fault memory, Car Fax or AutoCheck, ask your insurance agent or broker to search for any collision claims history, test drive, service records.

This is what melted pistons scoring & piston slap looks like.

This is what melted piston slap & cylinder scoring looks like.

we cleaned the pumps since we had to take them off anyway. The valves will be changed along with all the other hard to get at stuff while the engine is out. thanks for the tip on the solenoids. I'll upload more pics as we go forward.

Hi Lewis. Yes We have all new vacuum lines gaskets seals O-rings breather hoses. We've already checked & cleaned the SAI's while we were waiting for parts. We also ordered some silicone boost hoses too. After it's all said and done I plan to put another 130K miles on this beast!

Hey guys. Sorry I posted a reply on the wrong thread. Update. Engine out and what mess. Long story short the timing chain is stretched t least one guide has broken the idlers are worn the coolant pipes seals are leaking the valve cover gaskets were leaking the breather hoses were broken and the exhaust is worn. I decided to install sport cats rear cat bypasses and a sport pipes. I'll keep ya posted.

Okay so engine out and rebuild underway. On getting the engine out we realized the right side cat braided steel had separated so now it's new cats and an engine rebuild. I figured in for a penny inn for a pound. I've decided to install sport cats and a rear cat bypass set up. I'll keep ya posted. Oh almost forgot. The timing chain is stretched at least one guide is broken the seals on the aluminium coolant pipes are leaking as we're the breather lines and oil cooler.

great post thanks

straight to knock. had not heard it prior to and no issues prior to the low oil light. 

Here's a video of my own engine - currently being rebuilt after 130K. you'll notice that after the SAI pumps shut off the light knock becomes audible. From inside the car you don't hear it at all. Ambient temps were mid to high 30's at the time. What precipitated this finding was a low oil light following which I opened the hood to find oil everywhere and oil some oil in the coolant - looks like it just happened. Seems the oil cooler failed and the fan was spraying oil everywhere & I had no idea until the light came on. Add insult to injury, further tear down revealed the Y-pipe had not just cracked but was broken so major leak there and also the check valve adjacent to the AOS on the left bank was also cracked. Mind you no check engine light during any of this. At this point I told the tech to just change all the breather lines and vacuum lines while he was in there. Before doing this though he did pull the valve covers (I seem to change the gaskets every 2-years anyway) and no damage to the top end was found so definitely a bottom end issue. My tech advised he doubts it's a bearing issue because the engine still runs strong and compression was good all around when he checked, just the knock. I'll keep ya posted.

P1000116.wmv

Roxie/Frank - check this out. 

Some very good advice here Roxie. As usual Messrs. Big and Weller are on point. I am currently having an expensive repair done on my '04 CTT for this very issue. It ain't cheap and is definitely not DIY for the uninitiated. If you have other options or choices of CTTs to choose from I would up my ante and look at maybe 955 Turbo S sans issues, or a 957 Turbo. Any money you may have saved by purchasing an inexpensive CTT with issues and the DIYing the repairs yourself, you can easily and probably equivalently put towards a newer CTT in better condition sans issues.

Well one thing we know for sure, the intake plenum is cracked. Tech smoked the engine first and the hose going to the AOS is leaking too as are several other lines. He hypothesizes that the cracked plemun caused an over-pressure condition in the system and may have damaged the VVT actuator because the tapping noise is coming from the right side (looking head-on engine) valve cover and from the center front engine cover (timing chain?). The forward portion of the gasket is where the main oil leak is coming from. They're tearing it down now to get a look at the oil cooler, etc...

I'll keep ya posted.