Have any of you guys with an SL65, or really any other 65, datalogged to see what your normal IATs were? I've been datalogging mine and it's been 93F out and my IAT cruising at 60mph is 160F. If I hit the gas and do a quick run it will jump into the high 190s. It seemed ridiculous to me so I took it in for service. After a week and a half in the shop and the bringing some outside expert in they tell me that this is "normal" and there's nothing wrong with it at all. Pump is "fine", they bled the system and it's "fine", no pinched hoses. It's perfectly normal. So does anyone have any data of their own or have any kind of spec sheet from mercedes about how the IC system should be working? The service dept here never sees 65s they say.

 

Way to high IATs. on a hot day cruising should be between 115-130. Climbing to about 155-160 at WOT. Idling for couple minutes it will climb past 160 but will quickly drop as soon as you get some air moving across the radiator. Take it to a place that is familiar with the v12tt. Many people are not familiar with properly bleeding the system, and these pumps are known to run and not flow properly. They might have heard the pump run and assumed that its ok.

 

JAYCL600 datalogged my IATs awhile back on his laptop. Those figures sound similar to the ones I was throwing when my stock IC pump stopped working. I don't recall the exact #'s, but I think after the bad IC pump was replaced we went back out to datalog it again. We hit the gas from a cruising speed and the IATs actually dropped because the IC pump was doing its thing with air cooled coolant via the heat exchanger.

I can see if Jay still has the datalog information on his computer.

Tom

 

DSMED is correct, 190 is way too high.

Nick

 

Either bad IC pump or improperly bled IC cooling system.

 

Well I ran all this by them and I agree there's something amiss, but they don't see it that way. They say the pump is working, but I don't think they've flow tested it to see if it's actually pumping They found that the ratio of coolant to water was way off so they drained and refilled the system and rebled it. They updated the ecu to the latest version. However after all that the IAT is hitting 178+ without any effort. 176 is the figure I got from the factory where the turbo wastegates open all the way and it's running 0 boost. It should be throwing a code then. Utterly frustrating.

Another thing I noticed is that the IAT seems to be very sensitive to throttle position. If I stop the car and put it in 1st with my foot on the brake and get it up to 2k rpm the IAT will drop sharply then jump back up when I let off. No extra airflow over the HE so is the pump engaging then? Service guys said the pump is supposed to respond to temp not throttle. Same thing on the highway, feathering the throttle the temp will climb to 170s. Give it a little extra gas and it'll drop to 150 until you let off.

 

On V12TTthe IAT sensor is located in the intake manifold after the TB and has very little airflow accross it when car idles. This is why it not unusual to see 150-170F temperatures when idling or cruising.

Now, under WOT it should drop down to 100-125F depending on ambient temperature.

To add more confusion to the matter, I have seen pumps fail intermittently and not to trigger any over-temperature codes.

My suggestion is to simply replace the pump with C30, it is under $200 and one hour labor.

Good Luck!

 

It doesn't sound like the dealer is going to resolve this. I would recommend throwing a Johnson CM30 pump and call it a day. Have the installer wire it run all the time when the ignition is on. I am not sure if anyone has an installer to recommend putting it in the Dallas area but it fits it the Bosch pump's location and should be fairly easy.

http://www.letmotorsports.com/mb.asp...0&category=all


Good luck!

Tom

 

I'm 1/2 tempted to do just that. Autoscope here will put in a CM30 for $175. However the dealership here are ***** about any kind of mod. They flip out and won't touch a car if it's had any mods done to it.

 

To be honest, it would be kind of hard for them to even notice it unless they were poking around the area behind the bumper cover.

Tom

 

I'm getting the additional heat exchanger that I bought from CPT (the same that Marcus has in his SL65 - see below) installed next week. I'll see if I can get C2Design to datalog some IAT's before and after. The only thing that might throw a wrench into this is that I already have the CM30 pump (first thing I changed).

https://mbworld.org/forums/3563556-post34.html

Maybe Marcus can chime in...he may have already got some datalog info...

 

Jon,

I have not gathered data yet, but I am working on updating my build thread. This heat exchanger, and let me emphasize this is from a preliminary evaluation, works miracles.

Again, I will be updating my thread soon.

-m

 

I looked over your thread and see you've had power loss problems too. I'm guessing heat is my problem, but I've never been 100% positive. It was running like this in early spring when it was cool out. My car is trapping 116-117, but the DA is +2100 and not sure what yours is like. I do have timeslips from last August in +2000 DA when it was trapping 120.62. Hmmm. I'll have them look into the ECU as a potential problem as well while they still have it.

Also curious as to how that huge HE is working out.

 

My DA was similar during my pass, but what sealed the deal were my dyno #s - not just my trap speeds. I thought heat was my problem at first but it was software. Damned software.

I haven't had time yet to log/goto the dragstrip with my new heat exchanger, but will post information when I am able to. It seems to me, at least initially, that it helps keep that torque curve nice and flat by helping keep heat down and allowing the ECU to keep timing/boost up - but that is somewhat theoretical.

-m

 

no need to wire the pump for constant on unless you are needing a cooldown from the track. rev the motor to 2000 rpm. the pump will kick on and stay running un til the engine is shut off. apeusa.com has the cm30 for 149$ shipped

 

2 weeks in the shop and counting. Now they say my ECU is fried and they have to replace it.

 

keep us in the loop as things progress

 

I was logging my IAT's just a few days ago on my S65.....at 70mph with 100 degrees showing on the outside temp gauge, my IAT's were 140-150ish. And, they would drop slightly when at WOT. I remember back in December when it was in the 40's here and I logged my IAT's one night and they were at 80 degrees.......talk about a difference in power.

 

Great, they put the new ECU in and got it programmed then took it for a test drive....and that's when the drivers side coil pack bit the big one. This thing is coming apart.

 

Man...I am sorry to hear about all the problems with the 65. I hope it works out...

 

sit tight brother, have them replace all coil packs...youre car was a monster when it was running properly, its tough to have patience when things dont go well but our motors are extremely finicky, your patience will be rewarded my man!!

 

Bro, I know this may sound crazy, but maybe consider shipping the car to a V12 MB tech who knows WTF they are doing. I mean the $1200 it would cost seems pretty meager given what you've had to put up with thus far.

If you saw my build thread, I posted about my recent V12 gremlins and how a good tech can make ALL the difference.

I'd at least give it some thought... trust me, from experience, there's nothing like the relief of having your car run right again... especially a 65.

-m

 

I am offering my services up if you require them. That is if you trust me.

Nick

 

I may take you up on that.

3 weeks in the shop: I have a new ecu, coil packs, starter motor, battery, a fresh mix of coolant, and a new inspection sticker. I plug in the scanner and....169+ degrees right off the bat. Peaked at 182 degrees and didn't even take it above 70 before I gave up. Oh, and the service paperwork says this is within spec, even though I gave them the spec and it says otherwise.

I'm taking it to have a CM30 installed and wired to run continuously tomorrow and see what that does. Then I shall explore other options.

 

Robert,

Record acceleration run from 60-130, and look at data - IAT, Ignition advance, Airflow est. in lbs/min. and MAP pressure.

Like I said before, under cruise IAT will be about 80-90F above ambient. Under boost it should come down to around 20-30F above ambient.