rooney2006

Hey y'all, it's been a while for me . Classes were a ***** and baseball has been a lot of work recently. So anywho,

I've developed a coolant leak somewhere under/on the side of my engine block. It's still just a steady drip - and I just noticed it when I was checking my steering components tonight and turned the car on and off to rotate the wheels for a better angle several times. The leak continues to drip for several minutes and then stops.

According to the search I did, the possible culprits are:

-the radiator/radiator neck, which doesn't seem to apply here at all, as the leak is on the opposite side of the engine bay
-some random coolant hose, which is possible
-the water pump, but this is unlikely as I had this replaced less than a year ago
-heater valve failure - which based on the location of the leak, seems the most likely to me.

Any thoughts or suggestions, guys? I don't have a car lift so I can only get so close to the possible source of the leak.


Also, completely , but one general question: how often should one replace one's cap/rotor/distributor/spark plug wires/spark plugs?

I've had my car for pushing 2 and a half years and I haven't touched any of the ignition components. I've noticed questionable performance and I naturally assumed it was just about that time for a tune-up.

GEDaggett

Possible culprit to your leak may be your head gasket. Look for water pooling on the engine block underneath where the oil filter housing is and other various spots. Head gasket is a common issue for the Benz engines

Federic0W124

so is the leak near the front of the engine bay?

rooney2006

nope, it's coming from the rear of the bay near the firewall - looks like it's coming from somewhere under the exhaust manifolds from the two cylinders closest to the rear of the bay. Not sure if that's cylinders 5/6 or 1/2.

Seems to be coming from directly above the transmission, but that could just be my viewpoint looking down from above as I don't have anyway to jack up the car enough to look from under.

rooney2006

the head gasket would be pretty much the worst possible case scenario, i believe. hopefully not, though i suppose that based on the location that would be plausible, or even likely. sigh.

GEDaggett

The gasket is susceptible to leaks to the outside in the passenger side front and back where the head has tabs of sorts for the water jacket and oil ports. If that is the issue you might have a stronger smell just after putting the engine under high rpms and or load. Take a closer look there to see if it may be the problem.

rooney2006

What should it smell like if that is the case?

Anybody tried Steel Seal or similar head gasket sealants? If the leak isn't major or it isn't the head gasket and is the freeze plug, would this be worth trying?

www.steelseal.com

rooney2006

bump? any more ideas fellas?

Kestas

Isn't that the area where the overflow bottle dumps to the ground?

rooney2006

I really don't know. Is that the case?

Kestas

It'll be up to you to ultimately find the source for the coolant leak. If it's coming from the coolant overflow, then the cooling system is either overfilled or there is unusually high pressure in the cooling system -- usually a symptom of a blown head gasket.

rooney2006

well, yeah, of course i'll have to get it checked out and taken care of haha. i just didn't know that was approximately where the piece of the cooling system that handled overflow was located. it's possible that i've overfilled the coolant though. i'm really not sure. i'll get it looked at asap though. thanks man.

vanwiek

On the M104 W124 the coolent overflow goes into a second tank that hides behind the passenger side wheel well wall. If the M103 is set up the same way the excessive coolant would first have to fill that second tank before running onto the ground in that area. See the attached pics, in the first pic the hose between the two tanks is missing. The other odd looking tank is the vacuum reservoir.

It does sound like it might be the head gasket, fingers crossed.

rooney2006

oh dear. looks like i should get it checked out much sooner than later. hopefully, it isn't the head gasket.

Kestas

One method I use to find coolant leaks is to pressurize the system with shop air. You'll have to get creative to set this up. Don't use more than 20 psi. Once it starts dripping, follow the leak to the highest point.

rooney2006

ah. i think i can fabricate that. i'll take some pictures when i get home later, and hopefully that may help us figure this out a little bit better.

rooney2006

thanks so much y'all. i really appreciate the ideas and knowledge.

demagod

one other way of checking the gasket is to look at the oil filler cap, if its coated with a mayonaise looking stuff, then coolant is emulsifying with the oil, a common sign of head gasket leaks.

Kestas

Checking for a blown head gasket depends on the leak path. If there is overpressure in the cooling system, the leak path is combustion gases into the cooling system, as is suspected for rooney's case. If it's coolant into the oil, then you get the mayonnaise you described. There are other symptoms. Not all blown head gaskets show the same symptoms.

YNVDIZW124

Well, one more idea that happened to me.... Have you checked the hose on the rear of the engine that goes from the block to the heater core? Sometimes it likes to crack and leak from the bottom and leave a little trail of coolant that will go all the way back to the transmission. Hope that's the problem because you can cut it and put it back and that's it. Or you can also buy a new one.

rooney2006

great. turns out it is indeed the head gasket. my mechanic was not amused that i'd waited so long to bring the car in. his shop specializes in bmw club racing, so they do some seriously high-quality work and outsource to a machine shop that does equally good work.

He said I should get the various manifolds ported and polished while I have the head off to replace the gasket. He said with labor that it would run somewhere between 2 and 3 K with the head work. I'm doubting I'm going to go through with it, I'll probably add some sort of gasket sealant to the coolant system and drive it until the engine has had enough.

Kestas

It sounds like you're losing the love for your car. Because I'm a DIYer, I'm not a big fan of mechanic-in-a-can products and prefer to fix cars properly. But they do have their use in cases where you're dealing with hospice issues.

You don't have to get the manifolds ported and polished. This is usually reserved for the DIYer or if you have money to throw at performance upgrades. Replacing the gasket and refreshing the head should run less, around $1 to 2K.

ZedStyle

yeah, for real, i don't trust those products.. are you in GA or VA right now? make some calls and get some prices man, there are tons of benz mechanics around ...

YNVDIZW124

Well, for 3k you can buy another one...cheaper solution that could last 3-4 years is a used engine from a rear ended 300e. shouldn't be more than 1k installed.

demagod

yeah, I was thinking that, get a new engine for less than that price, Porting and head work is only gonna make much difference when you do cam work, pistons etc.