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I've sprung an oil leak

10K views 9 replies 6 participants last post by  steveg  
#1 · (Edited)
Hello everybody. I have LED lights on the ends of my axle tube and I noticed the other day one was burned out. So I crawled under the back of the car to replace it. I just happened to notice there was a drop of oil hanging off the bottom of my Bosch oil filter. A closer inspection and I found a couple of drips hanging of the timing cover bolts on the "towards the rear" side of the engine. I immediately thought that the front crank seal might have been leaking. I thought that because I just could find no way to hold the pulley and torque it per the procedure that All Data called for. I broke the original pulley trying to hold it from turning to remove it ( they are cast pot metal) and I was afraid of breaking the new one, so I torqued it best I could. There was a little oil residue on the inside if the bottom pulley. There was residue on the plastic bottom cover and I also found my new A/C stretch belt to be moved to the inside towards the engine by "one groove" and riding up on the outside of the pulley. I then checked the engine oil and it was right on full. So then I thought maybe a blown a/c compressor seal, the a/c works. It's got less than a thousand miles since the head work and I've been driving it like I stold it. They are working on interstate and of a morning our entrance ramp is a stop sign and then a big hill. When I launch from the stop sign you have to beat traffic coming down interstate so it regularly sees 6 grand in the first 2 gears just to get up to speed. So maybe I blew a gasket...wait a minute there isn't a gasket on the timing chain cover, it's blue permatex as the rebuild gasket set didn't come with a replacement gasket. Even originally it had some type of black gasket sealer on it. I torqued the bolts properly and was meticulous about every step of re-assembly. So this weekend I'll investigate further, but I thought maybe someone might have a heads up on area's that are prone to leaking on the 451. DCO

Also does anyone know the story on whether there is an aftermarket timing case cover gasket available? Or is it a MB requirement that a certain type of sealer be used instead?
 
#2 ·
I had to drive Max to physical therapy this morning and I kept it below 4,000 rpm. I verified the A/C is working fine even though the belt is one groove off. I don't know what happened there. I'm sure it was right when I put it on. Maybe some of those 6 grand revs did it ! Oh well I'm going to remove the passenger side rear tire and the plastic cover again and give everything a once over. I'm gonna check for compressor alignment and be sure the mounting bolts are tight. Also going to re-torque the water pump pulley (inch pounds). It's going to be hard to tell where the leak is because the engine is bright and shiny clean and the oil is almost clear against the block because it's clean. But I'll investigate and then update. I'm surprised, lots of readers, but no advice from anyone......Don't be scared....It's only me !!! Happy 4th everybody......have a hamburger and a hot dog from the grille and pop a cold one on your back deck. Then before the day is up go and give that Smart a washing before evening fireworks.....DCO
 
#4 ·
First, running the engine up to 6 million rpm will not cause the timing cover seal to leak. If the pcv system is blocked then excessive crankcase pressure can cause rubber seals to leak. I don't think there is any typical area for oil leaks. If the timing cover is sealed properly it should not leak so soon. Properly means use of the appropriate sealant and according to the factory service procedure and sealer maker's instructions. More sealer is not better. No actual gasket exists for this application, as far as I know, nor would I use one.

The easiest way to pinpoint the leak is to use ultraviolet oil dye. The dye is put in the oil and the engine is run to circulate it. When the leak shows up the dye will fluoresce under the UV light. It should be used with the yellow tinted glasses made for the purpose. Follow the trail of the dye back to the leak. Clean the area of oil residue first for best results.

The quick and dirty way for a back-yard method would be to use some type of white powder, such as talcum powder or Comet cleanser. You spray that on the accumulated oil residue and watch it turn dark where the oil is leaking out. Unfortunately, since you have spit-shined your engine there is likely not enough oil residue and grime build up to allow the powder to stick to the engine.
 
#5 ·
I drove the Smart all day yesterday. I put it on jack stands this morning and crawled under with trouble light and rag in hand to investigate this leak. It was bone dry except for one drop of oil hanging off the belt tensioner.
Just a couple days before I had oil on the back side of the muffler, the inside of plastic belt cover, back facing edge of the engine above the oil filter and the inside edge of the bottom pulley. I thought that the oil filter gasket leaked (squirted out) a little or I had a timing case cover starting to leak.
RR my train of thought on the redline RPM was because I would think the timing chain would be throwing off oil with more inertia at 6 grand than at 2, and that a borderline place to leak might leak at a higher RPM, bur not at a lower one, but I was probably wrong about that.
I put the A/C belt back in proper alignment. I felt around everywhere for a tiny leak along the timing cover and checked around valve cover gasket. I'll just keep monitoring the situation. I feel like the boy that cried wolf ! I have no explanation, but as long as it stays dry I'm happy to let it be. I can't have dirty old oil leaking on my nice shiny engine !! lol Thanks....DCO
 
#7 ·
That's the crazy part Papermaker, it was still on the full mark. It's a mystery. It didn't leak enough to be noticable on the dipstick.
There's another car site that had a lengthy discussion on Marvel Mystery Oil. Some swore by it to keep an engine clean and carbon free and NO leaks from thinner oil. Others swore that they started using it and sprung oil leaks. Others said well you had an oil leak to begin with and dirt and debris stopped it on the outside of the engine plugging up the leak, and then when you added MMO it cleaned out the debris and dirt and the leak surfaced. Everyone has an opinion and they are adamant pro or con on the subject. I have the opinion based on others testimonies on THIS forum that for OUR Mitsubishi engines it is a good idea to add it. Did I spring a leak because of MMO ? I would say no, but I did get a minute leak somehwere. But if it is just a situation of viscosity difference to cause a leak from a marginal area of gasket, MObil 1 synthetic like Mitsubishi calls for is pretty thin to begin with. I thought that the oil filter sprayed a little oil or the pressure switch above it sprung a leak, but the filter was tight ( I couldn't tighten it by hand nor loosen it). Like I was told months ago in an earlier post DCO is OCD about Max.
I am, so I'll keep an eye on it and if I see any more leakage I'll report back. DCO
 
#8 ·
Well it's been 5 more days and I've driven the car and the oil leak is back. I jacked up the car and got under and removed the plastic shroud the the oil splatter is around the oil pressure sending unit and oil filter. Oil is on the inside of the bottom pulley and blows back on the muffler just enough to make a smell. The belt tensioner is soaked and if were connected to oil in some way I would swear that IT was the leak! Oil on my new belts can't be good for them.
This weekend I'll try to raise the car and run the engine just enough to pinpoint it. It seems to leak more at highway speeds. I just added about 8 ounces of oil so that's the amount of loss over about 1 week. So if I can't pinpoint it for sure I'll just replace the oil sending unit and filter and if it still leaks it has to be the front crank seal. I don't think its the seal as the whole area would have oil residue on it. The alternator side of the front of the engine is dry and no oil. It'd just a pain right now. I use the Bosch 3000 oil filter. On Rock Auto they have them for just under $4.00 whereas at the local Auto Zone they're $6.99. Found the pressure switch somewhere online and it was just under $20. I'm not a tightwad by any means. but I hate just throwing parts at a problem.