May have blown the motor - Page 2 - PeachParts Mercedes-Benz Forum

#16 05-19-2011, 06:32 PM

Quote:

Originally Posted by barry123400

I totally agree about a shut off but a low pressure audiable warning is too long overdue for installation on these older cars.

Twenty dollars and a little time just might save your engine. Otherwise the chain and sprockets plus the tensioning device on the oil pump should be scrutinized and the oil hoses to the heat exchanger changed out if they are of an unknown vintage.

You might get by with a comparison squeeze test of the oil cooler lines in comparison to a new cooler hose. Soft spots or softer overall is rot. Your engine is at risk otherwise to some extent without an audiable device.

In the last couple of weeks there would have perhaps been two engines still functioning properly if they had one. Impossible to say how the person that loaned the car might have reacted though. Any individual that installed the alarm himself would have reacted properly in my opinion though.

I agree. I replaced the 18 year old hoses when I first bought my car because they looked grungy. I replaced both the hoses and cooler again about 10 years latter because the connection on the cooler was messed up and I didn't trust it. I recently spent about $7k putting an engine in the car, I don't want old hoses. The audible device is probably a good idea, someone should market a kit.

engatwork · #17 05-19-2011, 06:41 PM

If they are continued to be run with a blown oil line they will "automatically" shut down

.

To the original poster - I'd suggest trying to find a good used engine.

Orv · #18 05-19-2011, 06:48 PM

One of my VWs had a clever two-stage oil pressure warning system. Below 2000 RPM, the light flashes if the oil pressure is below 0.5 bar. Above 2000 RPM, the light flashes and a buzzer sounds if the pressure is below 1.8 bar. This saved my engine one day when I blew an oil cooler seal; when I heard the buzzer I immediately pushed in the clutch and coasted to a stop. Before I shut off the key I glanced down, and I still had some oil pressure. The last bit of oil that dripped out of the leak was frothy, so the pump had finally pumped all the oil out of the pan and started sucking air.

#19 05-19-2011, 06:49 PM

Quote:

Originally Posted by engatwork

If they are continued to be run with a blown oil line they will "automatically" shut down

.

Hopefully not until the car is safely out of traffic.

#20 05-19-2011, 06:52 PM

Quote:

Originally Posted by Orv

One of my VWs had a clever two-stage oil pressure warning system. Below 2000 RPM, the light flashes if the oil pressure is below 0.5 bar. Above 2000 RPM, the light flashes and a buzzer sounds if the pressure is below 1.8 bar. This saved my engine one day when I blew an oil cooler seal; when I heard the buzzer I immediately pushed in the clutch and coasted to a stop. Before I shut off the key I glanced down, and I still had some oil pressure. The last bit of oil that dripped out of the leak was frothy, so the pump had finally pumped all the oil out of the pan and started sucking air.

Sounds like a good design, but I'm not sure if there is a cost/benefit from the manufacturer's point of view. They have to weigh the cost of the alarm feature against the probability of a car losing oil pressure while it's still under warrantee and the probability the the driver will react quickly enough to save the engine.

Orv · #21 05-19-2011, 06:59 PM

Quote:

Originally Posted by Craig

Sounds like a good design, but I'm not sure if there is a cost/benefit from the manufacturer's point of view. They have to weigh the cost of the alarm feature against the probability of a car losing oil pressure while it's still under warrantee and the probability the the driver will react quickly enough to save the engine.

Yeah. Germans do love to over-engineer things, but it was pretty expensive for the benefit they were getting. It needed an extra pressure sender and an extra circuit board in the instrument cluster that tied into the tachometer. This was a fairly well-optioned car that also had voltage, oil pressure, and oil temp gauges in the console, though.

The VW 0.5 bar pressure switch has M10 threads. I'm not sure what size the fittings for the Mercedes oil pressure gauge are, but if they're M10 adding a warning light might be as easy as getting the VW switch, a tee and close nipple, and a bulb... I've thought of taking the cluster apart and sticking an LED in next to the gauge.

babymog · #22 05-19-2011, 07:25 PM

Our Prevosts have an engine alarm, which starts a shut-down countdown. You can override by pressing an override button. This sytem prevents shutdown in an emergency.

netboy · #23 05-19-2011, 07:43 PM

An alarm would not help in the case of an 18 year old driving 90mph with the radio up as loud as possible

, but it is a good idea. Shame about this car too, I had this thing shifting so smooth, lots of power, and frosty A/C and European headlights.

Oh well, win some, lose some. I'm going to sell it for $650. I've got $900 in it. Whats the going price for an MB that has a 4 milke radius? I can get $500 at Pull a Part but would rather someone buy it. Whats a fair price for a set of Euro Lights?

funola · #24 05-19-2011, 08:30 PM

Quote:

Originally Posted by netboy

Gave a 1983 300CD to a 18 year old for a commuter car who needed some help. The engine had a fresh tune up and usually driven 70 mph for 60 miles a day. The oil lines were less than a year old when one of the lines blew out of the swedge 30 minutes after the kid left with the car.
...

Please post what brand oil line. Were there any signs of leaks before they blew? Kinda freaky.

netboy · #25 05-19-2011, 09:03 PM

Absolutely no leakage. No sign of decay at all. Were purchased from Performance Prod. on line. Should have kept my leaky originals.

#26 05-19-2011, 09:26 PM

Quote:

Originally Posted by netboy

Absolutely no leakage. No sign of decay at all. Were purchased from Performance Prod. on line. Should have kept my leaky originals.

My indy says he will only install OEM oil lines because he once had to buy an engine for a customer after installing an aftermarket line.

layback40 · #27 05-20-2011, 02:21 AM

Quote:

Originally Posted by Craig

My indy says he will only install OEM oil lines because he once had to buy an engine for a customer after installing an aftermarket line.

X2
I know from hydraulic lines on my earth moving gear that what looks good often isnt.
I would never buy hydraulic lines on line from a "performance" type of company.
For the oil lines on equipment worth probably 100X a 300CD, only genuine is good enough.
With aftermarket you can never be sure what you get.

Stretch · #28 05-20-2011, 02:49 AM

A quick search on google suggests that low pressure oil alarms are quite common on marine engines. But here's an untested circuit for you DIYers out there:-

http://www.tbarnes.co.uk/TimsPages/CATERHAM/OilPress.htm

funola · #29 05-20-2011, 08:35 AM

Can you post pics of the blown oil line? Was the ferule not fully crimped? Have you contacted Performance Products about it?

netboy · #30 05-20-2011, 03:55 PM

Yes, the line blew at the crimp. The oil lines were purchased from the previous owner. I know they are less than a year old because I helped him drop his a/c compressor to install them. The oil lines I replaced the blown one with are locally fabricated and rated to 5000 psi. Should hold 60psi.