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If you've seen my other thread you'll know that I have been working on trying to suppress the top end noise that seems to be inherent in the C36 engine. I know that it is temperature related, so my first step is to get the car to run cooler. Being in Florida and mostly doing in town driving, the car usually runs right around 95*c. The factory fans kick in at 105*c, and in my opinion, that's too high. My goal is to keep the car between 75-80*c. I know that there is the "cool harness" out there, but that only makes the the fans kick on at 95* which is still too high, plus, it's just a $20 sensor with a resistor soldered in, which I could make myself so I cannot justify the $95 price tag.
My plan is a little more in depth than that. My plan is to use an electric fan in place of the mechanical fan. The electric fan will be driven off of a temp switch that I have installed in one of the available ports in the water pump. The switch kicks the fan on at 82*C and back off at 76*C. I have also installed a T-stat that opens at 77*C. Just with the T-stat, the car is al ready running cooler, but not cool enough.
I had hoped to already have the fan in and testing it, but the company sent me the wrong fan, and it's too thick. So while I wait for the new one. I decided to go ahead and wire everything up. My plan was to make everything as seamless and factory looking as possible. The temp switch that I ordered from Summit came with a relay and wiring, so last night I turned this mess of colored spaghetti-
Into a complete, plug and play, electric fan harness for a w202!
I used water proof GM style connectors and heat shrink on everything, I wanted this thing to be the best quality that I could produce. The harness plugs right into the car, no splicing anything at all. It also looks factory when installed, and most of it is hidden under the plastic covers of the factory loom. I installed the harness last night and tested it and it works perfectly!
Once I get the fan in, I will probably do the resistor mod to the factory coolant temp sensor to make the factory AUX fan kick in at 95*C, just to be safe incase there is a really bad Florida day. This whole set up will keep the car cooler than the "Cool Harness" for not much more money. Definitely more bang for the buck. I may even start making more of these plug and play E-fan harnesses if there is any interest. After my "Cool Pack" is complete, I will also be working on an oil cooler for the car.
The normal C36 Diesel sound has to do with the temperature of the oil as it's the difference in oil pressure that attributes to the diesel sound when the oil starts warming up. If you want to even "suppress" it you'll have to be running the oil at a VERY cold temp which would be VERY bad for the longevity of your engine. Let alone try to keep the coolant temps well below 60 degrees to keep that oil cold. That's why it has never been done and just left alone. If you don't like the diesel sound then just sell it! That's what you get when you purchase a hot rodded AMG. Instead you SHOULD be in it to make it run cooler so you don't get the power loss when the temps increase above 80 degrees.
I know that I won't be able to get it to go away completely, but when the temps are down, it's still there, but bearable. When the temps are up, my car is far louder than most (you can hear it with the windows up, radio on and AC on full blast... and that's just not right). I don't mind it when it's quieter. But when it's louder, it really sounds terrible.
As I said in my other thread, this may be normal for the c36, but it is not right. And that is attested to by the fact that the sound is intermittent. After a long highway trip, for example, even at higher temps, the noise is gone, but after it cools and warms back up to the same temp, it's back. A small oil cooer should help, but it won't cool the oil to the point of being bad for the engine. This car should have had an oil cooler from the factory. Why would you equip other m104 powered cars with a factory cooler, but not the modified m104 in the c36?
I've driven my C36 for long and hard trips on the highway and the diesel sound is still there just like it was when it first warms up so I'm not too sure who the hell came up with that. If anything it got slightly LOUDER after a very hard and long run. Never once has it gone away after a very hard and long run. Maybe 5 years of ownership isn't long enough I don't know. And yes I agree that just a simple oil cooler won't make the oil cold cold I wasn't emplying that, I just stated that you will have to get the coolant and oil temps WAY down to below safe operating temps to "suppress" the noise.
And yeah if it is indeed THAT Loud then I would be questioning it myself as it being THAT Loud is not really normal from what I've always read and experienced myself and others, mine will be audible just enough with the windows down and radio and blower off, Thats about it. What oil and viscosity are you running btw?? As that makes a big difference....
Last edited by BenzMaster19; 10-31-2014 at 04:39 PM.
I'm running 5-40 now. I had 20-50 before. Noise was about the same with both oils.
I took it on a 150 mile round trip the other day. About 90% hwy driving at 75-80mph. When I got there, I pulled through a toll booth I noticed that I didn't hear it with the window down, so I pulled over, popped the hood and nothing. No diesel sound at all, even with an ear close to the valve cover. It sounded just like it does after a cold start, it was very strange. It eventually came back after I stopped off for dinner and it cooled off, but it was quieter this time. More in the range of sound that I think you are used to on yours. That I was fine with. I could barely hear it even with the windows down, and even when I could, it didn't sound bad... just a little hint of a cam... performance engine like you were saying.
But when I have the high temp days, it's really bad. That's why I am hoping that the E-fan stuff and an oil cooler will help. Even if it just gets quieter. At the very least, I'll have a car that runs much cooler, lol.
I'm sure you already have, but make sure you grease the hell out of them. Or you will be pulling them back off when the squeaking gets so bad you can't stand it. I went lazy man route and installed grease fittings.
Haha, yeah, I greased them during assembly. Did you press in new roll pins (or press out the one from the old arms and repress them into the new ones)?
In other news, I found yet another car to save from the crusher.... (the 944 not the e28, that belongs to my friend)
I'll post up some better pictures when I pick it up on Monday. It's sitting at a friend's house 100 miles away. I bought it sight unseen and he picked it up for me.
sweet, for sure post up some pictures. Old Porsches should be saved. Here's a 928 that I found covered in chicken poop left to die in a barn. All that was originally wrong with it was the keys got stolen when his son threw a house party. The owner got a new key from the dealer using the vin but when it showed up the key was wrong. He bought a whole ignition set but lost interest so it sat for 7 years...
Thanks. I hope I didn't get in over my head on this one, but even if the engine turns out to be crap, I only paid a little over scrap price for it. That 928 looks pretty clean. How is the auto trans on those? My last 944 (7 years ago) was an auto and it was awful! I vowed to never own another automatic Porsche, lol.
Yeah It cleaned up nice. But for sure a 10 footer on the paint. The whole car was crows footed but what was still there shined up nice.
The interior I went through and cleaned up/upholstery painted/replaced most of the easy things but left the expensive stuff. I bought the car with the pure intention of saving it from a early death and then flipping. It only had 76,ooo original miles and everything was there. But just like yours, the automatic was pretty poor. Plus for being a v8 it was very underpowered but it had some Interesting technology for 1979. With the rear mounted tranny and fuel injection. Plus the doors, fenders and hood were made out of aluminum. It also had a kinda passive rear steer that would toe the rear wheels in when braking into a corner. It was a Lot of fun to drive but it needed a manual box and at least another 100hp (kinda like the c36 ) I'd love to try it again as a newer gts.
I always liked the look of the 944's plus there is always that turbo option. What's the plan for this one?
No updates for now. The C36 is kind of on the back burner for a while. I am currently focusing on some family stuff.
My friend with the e28 bought the Porsche off of me. I found out that it had been sitting for about 15 years, so it was a bit more than I wanted to get into right now. They will eventually be building a track car out of it.
Idk, its hard to judge the market on it when there really inst much of a market to speak of. I'd like to get $4500 as it is, but I'm not sure if that's asking too much. Thoughts? I mean, you guys know all the work that has gone into this thing.
If I could, I'd absolutely give you $4500 for that car. But I already have 2 C43's and the wife is absolutely adamant I get no more cars until we get her into something newer.
Think that's a totally fair price. Especially for what you have in it.
When it sells, what are you gonna replace it with?
Well, I'll probably replace it before I sell it, as I sold the wife's Jetta last night. I have, for a very long time, wanted something newer... later model... well equipped. I started a new job recently, and then very quickly got promoted to management of a new department, so I think it's time that my wife and I spoil our selves a little... My new job happens to be at a dealership and we have a 2009 Audi A4 Quattro with the Premium Plus and S-Line packages. And depending on what the bank tells me tomorrow, I might be able to get it for a steal. The plan is to sell the C36 and use the funds from that to get an SUV for my wife now that she is a Stay At Home.
Originally Posted by Sulaco
If I could, I'd absolutely give you $4500 for that car. But I already have 2 C43's and the wife is absolutely adamant I get no more cars until we get her into something newer.
Haha, well let me know if you change her mind! lol
Yep. I needed something newer and bigger, and more family oriented, while still being sporty. And while it is underpowered compared to the c36, it is a bit quicker, and can easily be made more powerful with a relatively low amount of money. I wanted the later model equipment, and I have to say, that the ride quality and handling of the A4 is far better than the c36. I really do enjoy driving the AMG, but I never quite fell in love with it. I love driving the Audi already. Its so smooth and refined, the AWD is great, and there is no turbo lag.
10-31-2014, 04:15 PM
