Higher temps=stalling?? Biocide?? - PeachParts Mercedes-Benz Forum

ajrn · #1 07-08-2007, 01:30 AM

81 Mercedes 240D 164,000 on the clock (clock was broken "awhile..") That's been fixed-- with instructions found elsewhere.. I highly recommend doing that!

Had it since February-- has some blowby, but starts and runs reasonably.. Not a powerhouse, but will cruise down the expressway 70+ without issue.

..except sometimes.

Twice now since I've owned it, it's 'lost power' and kinda slowed to a stop. Acted like a plugged fuel filter/fuel starvation situation..

Air and fuel filters have been changed since purchase. The primary looks fine...

Both times, I was near half a tank of fuel.. I added about 4 gallons, and it would start.. Wether this actually had any bearing on the real problem, or it was something else, that corrected itself, while I added fuel-- dunno..

Both times also, the engine was 'hot' (as in had been running for some time-- temp gauge consistently reads ~90C) and it was 85F or better outside. Again-- not overheating, but not just started in the driveway, and leaving home.. I'd say both times, I would have driven around 10 miles when it acted up..

I've since installed a pyrometer, and on the expressway, my temps are right ~900-1000F. Obviously higher, while I'm trying to merge-- and briefly to the 1250F range..

Idles good, starts easily.. And again, after BOTH episodes-- I drove the wherever I needed to, without further issues..

I'm wondering if I've got "alge" "fungus" "diesel bug" whatever..

I bought http://www.westmarine.com/webapp/wcs/stores/servlet/producte/10001/-1/10001/141700/377%20710/0/diesel/Primary%20Search/mode%20matchallpartial/0/0?N=377%20710&Ne=0&Ntt=diesel&Ntk=Primary%20Search&Ntx=mode%20matchallpartial&Nao=0&Ns=0&keyword=diesel&isLTokenURL=true&storeNum=6&subdeptNum=169&classNum=764 (Starbrite Star Tron Diesel additive) which is supposed to kill and enzymatically dissolve the funk in your fuel-- so it can be filtered or burned.. (Sounds hopeful to me-- but unrealistic).. For $12, though, I thought I'd give that a shot, before I drained and dropped the fuel tank.. (anyone who's done that understands why, right??)

Yes, I DO carry spare primary and spin on filters-- and tools to change both..

I put an two ounces in the tank-- 1 oz is supposed to treat 16 gallons.. I didn't know if the tank was 20, or 25.. It looks like the first "dose" is supposed to be twice the 'maintenence' dose-- so I figured a little more is what it's looking for.. I filled my tank, drove it home, and am "planning" to let it sit the weekend-- to let it do what it's going to.. (Supposed to be 95F tomorrow)..

Just wondered if anyone had used a biocide before-- or if anyone had another idea what my 240D's issue is.. The last time it put me a smidge late for work-- and it wasn't an issue, but I don't want it to be a problem for my g/f, or when I need to get somewhere in a more timely fashion..

Anything else I should be looking at??

Mister Byrnzoil · #2 07-08-2007, 08:57 AM

with the tank half full (or less), parked on level ground, when you change the primary fuel filter, does fuel flow freely out of the line from the tank?? if it does, your tank screen is prolly ok.

next time you lose power, you also might consider reversing the fuel line and the return line to see if there is any change. My coupe has been runnnin this way for about 2 weeks now.

I have used startron as well as several other biocide products, they worked well enough that I did not have to drop my tank(s), but I sure clogged primary filters every 500 miles.

kerry · #3 07-08-2007, 09:30 AM

Is it possible your fuel gauge is wrong and you are really running out of fuel?

This is the first time I've seen pyrometer temperatures for an NA posted on this board. 1250 seems quite high to me. Is the 900-1000 just cruising on the flats or under full load while accelerating?
I've got a Cat 3208NA in my motorhome with an aftermarket turbo, I only see 900-1000 when climbing long steep hills and only saw 1100+ when it was getting overfueled as a result of a very dirty air filter and climbing steep hills. My pyrometer is pre-turbo.
I'm quite curious as to whether anyone has any comparative numbers. 1250 without piston oil squirter coolers seems to be pushing the limits for the pistons.

Mojool · #4 07-08-2007, 12:08 PM

i kept having issues with fuel starvation near 1/4 or less...turns out my tank screen was GUNKED up pretty badly (like almost all of it except for the top of the screen was completely blocked up).

Mister Byrnzoil · #5 07-08-2007, 04:48 PM

Quote:

Originally Posted by Mojool

i kept having issues with fuel starvation near 1/4 or less...turns out my tank screen was GUNKED up pretty badly (like almost all of it except for the top of the screen was completely blocked up).

did you ever use biocide?

ajrn · #6 07-11-2007, 08:02 PM

I let it 'sit' tank full, since Saturday.. Took it out for about 6 miles on the xpressway today.. Seems to be okay-- again, today was cooler, so who knows, if I've changed anything but the weight of a few bucks in my wallet.

I did reverse the lines in my VW pickup, once when I had a fuel starvation problem.. I guess it's still that way.. I pulled the motor when I blew the headgasket and NUKED the rings.. I haven't had time, $$'s or inclination to get at it yet..

<---it's always sumthin..

ajrn · #7 07-11-2007, 08:07 PM

BTW-- the avitar pic is Rudolph Diesel...

sigh.. My Vegoily Hero.. Well, and McDonald's fries..