i have been looking at older posts and haven't found a solid answer to my question... so my questions is i have a 2005 cl65 and factory says this car should boost stock 1.5 bars about 22psi (max) so i recently hooked up a boost gauge on my cl65 and i have basic upgrades ecu/tcu tune and cat-less downpipes with a knn filter with upgraded front cooler and pump.. i would assume that the upgraded tune should provide me with boost reading in the low to mid 20's (21-25) psi but my gauge showed me a boost reading of 15psi and a spike of 19 psi, does that make sense to any one? or do you think my tune got deleted some way? i did dyno with ecu tune 584 hp but after the dyno, i installed the tcu tune, air filter, front mount cooler. and catless downpipes so i am hoping close to or over 600hp

I know my car runs much better in cold weather. If your testing in L.A. on a hot day my thoughts are your boost would be down because the air charge is running hot. HST maybe your cooler pump/system is skewed. I'm sure someone else will share an opinion. What ecu/tcu tune do you have ?

15 psi is low. can you put the car on the dyno again to see what kind of power it makes.
I would also connect the MAP sensor to the boost port on the dyno so you can plot the boost curve on a graph.

i made a appointment with my tuner ( OETUNING ) to find out whats going on with my car, i hope i dont have a misfire, and the ecu is controlling boost to protect the engine

If its a misfire you'll know ALL about it, you'll be down to six cylinders. Low boost won't be so obvious; I'd suggest using OBDII diagnotics and a smartphone or laptop to track what inlet temp and pressure are doing.

If your I/C pump had stopped working (not easy to diagnose in itself) then that would lead to high IAT, and that will cause the boost to back off. But the IAT really does have to be high, I don't think its a normal occurence. In ordinary hot conditions the ECU will just retard the ignition, which has a similar effect.

Nick

every now and then i check to see if my after-coolers are hot after a hard run, but they are surprisingly cool to the touch.. do you think that would be a good way in testing if my pump was working properly besides hooking up the scanner.. average temp in L.A is around 80-90 degree during the day time

i do have a upgraded pump, front cooler with distilled water with water wetter installed ( bled properly )..


if anyone has a tuned cl65 and knows what boost levels they are running... that would be helpful so i can cross reference with my car

FSB did you replace your coil packs recently? If yes and you did it by yourself for the first time it is very easy to incorrectly bolt the clamp from the turbo outlet

can you describe more in depth about the turbo outlet pipe issue

it is very hard to explain. I pmed you my number it will be a lot easier for me to explain it over the phone.

This.

Btw, checking the h/ e pump is easy. As the hot engine is running check the two shrewder valves next to the aftecoolers. If they shoot coolant when pushed momentarily - you good. No strong stream- problem.

thanks buddy

Shardul, are you saying you can have a boost leak if the turbo return pipe isn't re-installed right? I'm trying to figure if that could be my issue.

That would make sense if you're talking about the line coming off the compressor of the turbo. If that's the case, the turbo's are too small to make up for any pressure loss in the system and will basically fall out of efficency causing them to become one big hair dryer dumping nothing but hot air into your engine.

R.K.

What is the trick to reinstall that pipe? I'm talking the turbo outlet to the intercooler piping. It seemed like you just jam it back in and put that (poorly designed) ring clamp around and screw it in.

Saintz, if you think you are having boost leaks, I would suggest getting access to a smoke machine. You will be able to pressurize the system and look for leaks a lot easier.

R.K.

I retightened that pipe. It wasn't loose, but it wasn't fully in line with where it should be. Still no boost. And it's tight enough that I don't see how there can be a boost leak from there.

At this point I think I have a waste gate issue. Anyone have a picture of the wastegate and how to diagnose an issue?

First we need to know what pressure the wastegate spring is on the CL600. If it was the wastegate sticking open, you could have a no boost issue. If it was stuck closed, you would be over boosting. If something happened to the vacuum source, you would get boost but only limited to the wastegate spring. The problem is that if you are getting zero boost on both turbo's, there is a bigger issue than you thought. The best is to put a boost guage and t it into the vacuum line on one turbo, take the reading and then do the other side. That way you can see if the wastegate is even getting boost/vacuum. If there is nothing there, you need to find a way to get a boost reading before the throttle bodies. There could be so many things. It could also be your blow off valves, map sensor etc.

R.K.

I have changed the MAP twice, so that is probably not it, unless that hose is clogged. Changed one of the airbox MAP sensors and that didn't help either.

Took it to get codes pulled in case there was a code even with no CEL. No codes, so it appears to be a mechanical issue rather than electronic, but not positive.

Wastegate stuck open seems to be it, but that means the computer is compensating to turn the other turbo off. I'm not sure how that's even possible, because the second turbo should still be limited by the minimum wastegate pressure.

There are no whistles or other noises to indicate a boost leak, although that's not always a guarantee.

Does anyone have a diagram of the turbos and boost lines? I can't even tell what's what. This all started when I replaced a coil pack. Reinstalling I pinched an EGR line which connects somehow into the turbo (but no idea why a EGR line would feed into the front of the turbo). I freed that line so it is no longer pinched, but still no boost. Also broke the MAP sensor when I swung the intercooler out of the way, but fixed that, and still no boost.

Any ideas appreciated.

^^If the map sensor was faulty or unplugged, your car would run like crap. It sounds like its something you did when you changed the coil packs. Are you sure you plugged everything in properly? Did the plugs plug in all of the way and lock into place?

R.K.

Plugs all went in fine. Coil seemed to go in ok, but can't be sure. The rear side was difficult to seat. I assume I would get a misfire code if the coil was bad or not firing, correct?

Hope this helps buddy

It is freaking hard to access any off the wastegates on the car.

That helps a ton, thanks!

Is the yellow component the diverter valve? I think I pinched the line running to it originally, but should be unpinched now. That would explain maybe if that valve is stuck open and so the turbo spools but it just dumps the boost right out.



Is Y31/5 the boost controller? I saw two valves that look like that by the passenger valve cover, but I thought they were EGR valves. That may be the issue as well. One of those runs the line that I pinched, but I think it ran to the diverter rather than the wastegate as shown in the picture.

Yes yellow component is the divertor valve.
Y31/5 is the some what of a boost controller it is located under the passenger side IC

Saintz, if your line is pinched to the wastegate, you will still see boost but only as much as the wastegate spring pressure. If you unpinched it, it should be working again. The boost control solinoid might be faulty. I'm not sure how one would check it. Finally, I will say it again, hook up a boost gauge temporarly. That will tell you a lot.

R.K.