Need Help: Cracked Head??? - PeachParts Mercedes-Benz Forum

wbredin · #1 09-05-2007, 01:32 PM

Hey guys,

my car: 1987 300d with the 603 12 valve

my story:

I've had a radiator leak for about 2 weeks. Since I know the 603 is notorious for having issues when it gets hot, I parked it. Yesterday I drove it to my friends shop. Before I left, i filled the coolant system with about 3/4 gallon of water. I figured that would be enough since the water level was at the 'normal' level and it was a short trip.

I drove it to the shop and was careful to watch the temp guage the entire time. At no point did it get anywhere over 80 degrees (very short drive...approx 3 min). So i parked it and got out to chat with my buddy...jump back in the car 30 min later and it starts but quickly dies....it has never done that before.

I try it a few more times and can only get it to run with almost full throttle for about 5 seconds before dying....it sounded exactly like it was starved for fuel.

Filled the coolant system to the brim with water...only took about 1/2 gallon more (approximately) before it was overflowing. Started again, same thing....

Took off fuel hose and made sure the lifter pump was working...it was...so i cracked a few injector lines and cranked to make sure it wasn't the IP...it didn't seem to be b/c there was fuel dripping out of the unscrewed injector line...

So now i'm stuck...what is the deal? when it does run, there is no smoke that I can see...but it only runs for a few seconds...would doing a compression test tell me whether I have cracked/warped the head? What do you think this is?

Thanks for reading

DieselAddict · #2 09-05-2007, 01:54 PM

It sounds to me like a clogged fuel filter or tank screen, except that you seem to indicate that the car is using a lot of coolant. If that's the case, it could be a cracked head or failed head gasket but if the engine runs perfectly with no smoke before it dies, then that's unlikely. How much coolant does it use and are there any external leaks? Do you have any oil/coolant mixing or residual pressure in the cooling system?

TX76513 · #3 09-05-2007, 02:13 PM

I am going with a fuel (filter) issue. Your D is not exhibiting the tell tale signs of a cracked head or head gasket failure. At most it is coincidental that it happened when it did. .02

TMAllison · #4 09-05-2007, 02:14 PM

You stated you have a leaking radiator.

You never stated the car overheated or ran hot.

That being the case, it sounds like not continuing to run after being succesfully started is fuel delivery or shutoff related.

DieselAddict · #5 09-05-2007, 02:42 PM

Quote:

Originally Posted by TMAllison

You stated you have a leaking radiator.

For some reason I missed that. I guess I was reading too fast.

TMAllison · #6 09-05-2007, 03:08 PM

Quote:

Originally Posted by DieselAddict

For some reason I missed that. I guess I was reading too fast.

Not possible to post 1-2000 times and not have to spit a few toes out on occassion. We've all been there.

wbredin · #7 09-05-2007, 06:12 PM

Thank you all so much for the response.

Your responses are giving me hope that the thing isn't completly dead...BUT, you didn't know this: there is no fuel fileter on it currently. I needed to do this for a few days before I reinstall my Davco fuel filter. So with that said, it can't be a clogged fuel filter, which would make perfect sense with the symptoms....

Another question: when i unhooked the lines from the injector nozzles and cranked it over, I did see a few drops of fuel, but not a 'jet' or 'burst' of fuel as i was expecting. I know that the IP sends the fuel out at high pressure and I was expecting to see it squirt out, but all i saw was a dribble... is that b/c it just isn't sending all that much fuel?

So assuming the IP has fuel, what other system could have failed to keep it from running? Could the IP have just died?

Thanks

TMAllison · #8 09-05-2007, 06:31 PM

Check the clamps on the section of hose where you removed the in line fuel filter. Is probably a leak there causing you to lose prime.

DieselAddict · #9 09-05-2007, 07:15 PM

Quote:

Originally Posted by wbredin

there is no fuel fileter on it currently. I needed to do this for a few days before I reinstall my Davco fuel filter. So with that said, it can't be a clogged fuel filter, which would make perfect sense with the symptoms....

Which fuel filter did you remove? The spin-on, inline, or tank screen? I don't see how you can even run the car without the spin-on filter. And if you removed in the inline (prefilter) one, then the spin-on filter could get clogged even quicker.

wbredin · #10 09-05-2007, 07:49 PM

Quote:

Which fuel filter did you remove? The spin-on, inline, or tank screen?

I removed the fuel filter which is mounted to the front of the engine. I believe that is the 'spin on' filter you refered to. The tank screen has not been messed with at all...and the prefilter is still on.

For the last little while, I have been running the car without the spin on and only relying on the small white prefilter to help out. I realize this is dangerous, but I was assuming it was ok for a short while.

Anyone know if an air bubble could be trapped in the IP? A friend mentioned this and it sounded like a possibility....

kerry · #11 09-05-2007, 07:52 PM

It's not at all clear to me how the engine can run without the canister fuel filter. Can you elaborate? Doesn't fuel pour out where the filter was?

Hatterasguy · #12 09-05-2007, 08:09 PM

How do you run the engine without the spin on? I don't think thats possible?

If the spin on is off, you probably just ran the fuel out of the IP. And made a massive mess over the front of the engine. Put a new filter on, fill it with fuel and she will probably start.

Is the coolant leaking out or being burned? Sounds like a wicked radiator leak, probably should not be driving it.

TMAllison · #13 09-05-2007, 09:37 PM

It's kinda helpful to get the whole story out at one time....causes less confusion and you get better help too.

Sounds like you are in the middle of a veggie plumbing mess when you developed radiator and hard start issues???

Hatterasguy · #14 09-05-2007, 10:08 PM

Oh this is a veggie car? That changes things. First you need to turn things back to stock, thats part of your problem.

wbredin · #15 09-05-2007, 11:14 PM

OK, so let me explain...its not that incrediable, but I did manage to remove the entire 'spin on' assembly and filter. I took the entire mess off, and bypassed it with a different filter: the Davco filter. SO no to worry about having fuel squirting all over the place; it is plumbed differently.

Since someone will then say : well revert it back to normal, I say yes, that might work, but then again, it was working just fine for months with the altered fuel system. And during this time I only ran veg once and even then it was cut 75% with dyno diesel.

So another questions:

Anyone know if there should be jets of fuel coming out of my injector lines when I take them off the injectors and crank the engine? All I have is a slow dribble...