Has my 300td been hacked? - PeachParts Mercedes-Benz Forum

stevekim · #1 06-07-2006, 01:55 PM

I have a favor to ask the group. I am attaching pictures of the engine compartment of my '83 300td and was wondering if anybody could tell me if it has been hacked. A friend of mine told me it's missing the black box that sits on top of the transmission which leads him to think that someone could have made questionable modifications to my car. He also pointed out that there appeared to be missing hoses but wasn't able to tell me what they were for. The car seems to run fine without these things but it makes me nervous to know that someone might have been tampering under the hood.

If you would like high res pictures please email me at histevekim@gmail.com and I would be more than happy to send you some. Thank you in advance. I would really appreciate some advice.

Thank You,

Steve
'83 300td
Los Angeles, CA

MonsieurBon · #2 06-07-2006, 02:44 PM

Looks like someone plugged your EGR and disconnected and removed the box that attached to it. My car had the same thing done to it and it seems to run fine.

JimmyL · #3 06-07-2006, 02:52 PM

Quote:

Originally Posted by stevekim

A friend of mine told me it's missing the black box that sits on top of the transmission which leads him to think that someone could have made questionable modifications to my car.

Uhmm, we usually call that the valve cover.

Looks like somebody bypassed your egr. Embrace that!

Quote:

Originally Posted by stevekim

but it makes me nervous to know that someone might have been tampering under the hood.

That is what we do here......

There may have been some tampering, but that appears to be a virgin alda cap sitting on there.....

andmoon · #4 06-07-2006, 03:12 PM

My 82 had a black box on the valve cover that was vac controlled....shut off and god knows what else.

stevekim · #5 06-07-2006, 03:24 PM

Thanks for the replies!

Hey, Jimmy. So are you saying that bypassing the EGR is a good thing? What the heck is the EGR anyways? :-) Sorry, I'm a newbie.

Steve

Eric Eliel · #6 06-07-2006, 03:33 PM

My California 84 doesn't have the black box and neither did my prev 84. Not sure about the '83 300DT CA version. If you are in the South Bay, stop by and look at mine. The line should be plugged but not taken off (just in case someone is snopping around smog check wise, yes I know we don't have smog checks for diesels here in CA).

EGR = Exhaust Gas Recirculation

Phil · #7 06-07-2006, 04:03 PM

See if these help.

sixto · #8 06-07-2006, 04:14 PM

Looks like the overboost protection solenoid is bypassed as well.

Sixto

arcticathlon · #9 06-07-2006, 04:18 PM

i have an 85 cali 300D and it does not have the black box you are talking about. i think many '84 and '85 have a computer of sorts that takes care of many of those older vacuum devices.

here is a pic of my '85.

stevekim · #10 06-07-2006, 04:57 PM

thanks for the pictures phil. they were helpful. i am attaching phil's pictures with a circle around the black box i was talking about. if you notice on my engine it is not there. the other circle is around the sort of wishbone rubber joint. mine seems to have a hose missing or stopped up. once again, i appologize for my non techincal terms. i'm new to this but i will try my best to learn.

the egr relates to exhaust, specifically as it relates to smog, no? in that case, since i live in so. cal. and don't have to smog my car will this cause any problems?

sixto, what is the overboost protection solenoid? what is effect of having this bypassed?

thanks again for your help. i really appreciate it.

steve

Phil · #11 06-07-2006, 05:09 PM

I will try to get a picture of the black box with out the cover tonight. Its no problem to run with out the EGR but I feel its better to have it there even if you disable it so if smog checks become an issue some day you at least have it installed. You definitely want the over boost switch on the fender connected and working as its a kind of engine insurance.

ConnClark · #12 06-07-2006, 05:09 PM

A bypassed EGR will not hurt the car. In fact it should help keep your intake manifold clean on the inside. You should also get slightly more power and slightly better mileage. EGR is used to control NOx emissions. It does so by slowing the rate at which your fuel burns allowing a more even distribution of heat in the prechamber.

Phil · #13 06-07-2006, 05:19 PM

I forgot to mention if any of the vac fittings are not connected make sure you plug the fitting until you decide if you are going to reconnect what ever went there. The over boost switch protects the engine from to much pressure from the turbo. If you doen't heve the switch get one. You could probably get one from the junk yard as there is not much to it. The switch goes in the line between the intake manifold and the ALDA (lots of info on the ALDA on this site).

pdxwaker · #14 06-07-2006, 05:59 PM

I don't think the black box has been removed from your car... my guess is that it was never there. Late model 300d's don't have the change over valve on top of the valve cover. My original understanding was that '85 federal and '84 - '85 california cars had the newer 'vacuum control unit' instead of the change over valve type of system. However, my '84 300TD federal doesn't have this and I'm pretty sure its original... maybe the wagons made the switch sooner than the sedans?

Phil · #15 06-07-2006, 08:55 PM

Quote:

Originally Posted by pdxwaker

I don't think the black box has been removed from your car... my guess is that it was never there. Late model 300d's don't have the change over valve on top of the valve cover. My original understanding was that '85 federal and '84 - '85 california cars had the newer 'vacuum control unit' instead of the change over valve type of system. However, my '84 300TD federal doesn't have this and I'm pretty sure its original... maybe the wagons made the switch sooner than the sedans?

If that cam assembly is on top of the valve cover then it originally had the black box. When someone removed the EGR they removed the two valves at the same time.