where am i leaking?

[turboaddict21]

hey guys,
For about the past month or so i have had an oil leak that hasnt been located. All i know is that my valve cover gasket was leaking but was fixed and that oil seems to be hitting the axle because it is getting thrown all underneath my car. My question is has anyone had this happen? Also, the mitsu mechanic said that the 420a has know to go through a head gasket or two and that the head (i think) might be warped or something. Any info would be great because it is going to the shop this next week.

Thanks,
Ian

 

[Pandagonier]

Check your valve cover for cracks. I had a crack on the top that went down to the side. I didn't notice it till I was reving my engine at the throttle body and seen oil just shoot out. Hope this helps.

 

[XMasta19]

hmm...possibly the notorious corner headbolt oil leak. check the rear drivers side corner of the block where the head torques down, let us know what you see

 

[destruckeclipse]

hmm...possibly the notorious corner headbolt oil leak. check the rear drivers side corner of the block where the head torques down, let us know what you see

I had the same exact problem, this seemed to be the culprit. I took that bolt out, cut it down, put in a new head gasket and everything was fine, well, there was no oil leak anymore atleast.

 

[baxsom]

exact same thing happened to me

it didnt leak a lot
but just enough that if it sat overnight
there would be a few drops on the floor of the garage in the morning

cut a few threads off
and good to go

 

[turboaddict21]

Well, I had the valve cover gasket just done some weeks ago and no cracks had been found but just like two weeks later I started to see oil on top of the valve cover again. When we changed it (gasket) the second from the right (if your looking into the engine from the front) spark plug was covered in oil. Would a leak from the gasket be enough to trickle down the block, onto the axle and get thrown underneath the car? Also, I'm going through a lot of oil. The spots in my driveway are nuts. Each is probably 2.5 ft in lenght and 1 ft wide. Anyways, it goes in the shop the coming Wed. and we'll see where it goes from there.
Thanks,
Ian

 

[baxsom]

when the VC was done did they put the silicon gasket maker on the joints under the VC.

and did they seat the spark plug gaskets properly.

oil on the plug usually means that the spark plug gasket in the VC is bad

also have you checked your mainseal

 

[turboaddict21]

BLAH!!!! So the car is at the shop and and this is the update. Oil is all on the back side of the motor and a little on the vc again. So far they think that it may be either the rear main seal? or head gasket. It seems to be leaking only when the car is moving but not during idle. They are going to clean all the oil off and start it up to see if they can spot the leak(s). I was told there might have been a recall for the head gasket.....true? Thanks again guys.
Ian

 

[Doug99RS]

I was told there might have been a recall for the head gasket.....true? Thanks again guys.
Ian

False. Never has been, never will be. It's possible that the rear main is leaking but most likely the headgasket. Also, cam sensor seal can look just like a headgasket leak if you don't know what you're looking for. Finally, there's also the oil pressure sending unit on the back side of the block that frequently leaks.

For everyone else, it is possible that the valve cover is cracked but the car is a 2gnt which I've personally never seen or read on here of a case where it was cracked. The 4g63's are the only ones I've heard of cracking.
Doug

 

[turboaddict21]

Thanks Doug for clearing things up. I have chosen to put on a new head gasket and see what happens from there. It gets ordered Monday and put on Wednesday. I went earlier to http://www-odi.nhtsa.dot.gov/cars/problems/tsb/results.cfm and there was a service bulletin about the head gaskets. Also, do any other 2gnt's have problems with the oil cap? Sorry about all the questions, just want to cover everything possible now. Thanks again!
Ian

 

[Doug99RS]

I've not seen any problems with the oil caps but if you've got oil leaking around it you might as well replace it too. Replace your PCV valve too while you're doing all this.
Doug

 

[hereitcomes]

Have you looked at the back of the engine? There is the oil pressure sending unit on the back of the block...these drip oil. Mine did. It needs a box wrench to be turned out of the block. Lift the car up and look straght up at about the dead center of the back of the block. See if it is leaking.

 

[gspears3]

Speaking of '95 420A (A/T) oil leaks, got a steady drip from bellhousing. Cleaned engine, checked VC, checked cam sensor, checked PCV, replaced Head Gasket (was bad, how I got the car cheap), checked Oil PSU, replaced oil pan gasket, finally replaced rear main seal (carefully!!!.) No dice... Someone mentioned a "cracked plug in block" but other than the freeze plugs and that wierd square head threaded little one in the back I can't find any other "plugs". Any help would be mucho appreciated...

 

[dr1665]

a steady drip from bellhousing.

Considering all you've inspected, I'd be willing to be you've got rear main seal problems.

The good news? It's a $15 part and takes less than 15 minutes to replace once you get to it.

The bad news? You have to either drop the tranny or pull the engine to get to it.

Have fun with that.

 

[4UH8ERS]

If its coming from your bellhousing and theres not oil above the tranny then you can bet its your rear main seal. If you say you have already changed it then you probably replaced it incorrectly.

only other place i could see it coming from would be the bedplate.(lower section of the block).

 

[Doug99RS]

I've seen a number of headgaskets leak and drip from the bellhousing. This is not to say that your hg is blown but simply stating that it could still be from up top. I've replaced a number of cam sensors lately due to hair-line cracks. The oil actually leaks through the connector, down to the headgasket line and then down the block like the typical headgasket leak.

I'd also like to throw in the possibility of an input seal for the transmission. I've not run across it before but there's oil in the trans too and if the seal is leaking it's going to be pushed in to the bell housing.

I think there are oil galley plugs in the head if I'm not mistaken. I'd recomend putting oil dye in the engine oil and wait for it to start leaking. If you check the oil residue with a black light and find no dye then it's probably transmission oil and not engine.
Doug

 

[gspears3]

Thanks all for the feedback. It's definitely coming from the area of the rear main (spinning out on the flywheel, engine side) but we were sooooo careful replacing that seal. Prev owner says she had a shop do that earlier and leak persisted. I'll let ya know what I find back there...
Gary

 

[Doug99RS]

Below are the destructions from the service manual. They use a special tool to install the seal which consists of a large cup p/n 6926-2 and a white teflon-like piece with a magnet on it p/n 6926-1. The magnet makes the pilot piece stick to the crank. The seal is placed on the end of it and the cup forces the seal in to the block evenly. The service manual CLAIMS that failure to use this could result in the seal "rolling" which will eject the spring inside the seal. This spring is what actually keeps pressure on the crank to prevent oil from leaking.

Now... everything I'm talking about here is basically going on the assumption that it's the rear main leaking. I don't know if that's it or not and ultimately you'll have to be the one to diagnose it since you've got the car. But... here's a few things to check out if and when you pull the transmission back out. In the picture showing removal procedures you'll notice them using a screwdriver. If used improperly the crankshaft or the block could be damaged to the point where a new seal will not prevent oil leakage. When you remove the crank seal make sure not to damage the crank or block. All of your force should be applied to the seal and don't beat on the screwdriver with a hammer to the point where you go through the seal and in to the crank/block.

Once you have the seal out check the crank and block for damage such as gouging, nicks, or bent metal. These imperfections must be addressed prior to installing the new seal or you will tear the new one and still not fix the problem. Use emory clothe or very very fine sand paper to try and smooth out these damaged areas. DO NOT use a die grinder with abrasive discs.

On the reinstallation you may want to use some RTV on the seal where the seal meets the block. There are several seals like a rear main seal that leak on the outside and not the surface that meets the crank/driveshaft/camshaft. I would recomend using ATF RTV or Engine RTV from the Dodge/Chrysler dealership.

Also make sure that when you reinstall the seal that you walk it in evenly making sure not to roll the inner lip thus throwing out that spring. Once you've got it contacting the crank using either the above tool (borrowed/bought from the dealer) or a punch that is the same size as part of the seal. Lightly tap it in going around the entire surface of the seal. Don't push one side in all the way and then try and go to the other side. Even and slow.



CRANKSHAFT OIL SEAL - REAR
REMOVAL
Insert a 3/16 flat bladed screwdriver between the dust lip and the metal case of the crankshaft seal. Angle the screwdriver Rear Crankshaft Oil Seal - Removal through the dust lip against metal case of the seal. Pry out seal
CAUTION: Do not permit the screwdriver blade to contact crankshaft seal surface. Contact of the screwdriver blade against crankshaft edge (chamfer) is permitted.

INSTALLATION
CAUTION: If burr or scratch is present on the crankshaft edge (chamfer), cleanup with 400 grit sand paper to prevent seal damage during installation of new seal.

NOTE: When installing seal, no lube on seal is needed.

Place Special Tool 6926-1 on crankshaft. This is a pilot tool with a magnetic base Rear Crankshaft Seal and Special Tool 6926-1
Position seal over pilot tool. Make sure you can read the words THIS SIDE OUT on seal Rear Crankshaft Seal and Special Tool 6926-1 Pilot tool should remain on crankshaft during installation of seal. Ensure that the lip of the seal is facing towards the crankcase during installation
CAUTION: If the seal is driven into the block past flush, this may cause an oil leak.

Drive the seal into the block using Special Tool 6926-2 and handle C-4171 Crankshaft Seal Special Tool 6926-2 until the tool bottoms out against the block Rear Crankshaft Seal - Installation

 

[gspears3]

Thanks again for the response! Too much oil around to tell if seal or oil galley plug (which looks driven in a bit too far.) Will replace both and pray. Will put some sealant around both bores (checking for burrs, etc.) this time. My Haynes says install dry, my Mitchell says oil the lip. We went dry last time... Also, you can get a large PVC flange which works perfect for seating it evenly and flush. Keep you posted. You do NOT want to do this job twice, trust me...
Gary

 

[gspears3]

Right again, Doug99... Pulled the seal and the spring was off. I'm guessing if you don't have that special tool you MUST oil the seal lip or it will "roll" the spring out like you said. If you check the bore with the seal out there's an edge where the bedplate meets the block, so some ATV is definitely in order, taking care not to block that hole at the 6'oclock in the bore... While back there replacing that little oil galley plug (shown on the diagram you posted, btw) seems like a good idea also, on my rebuilt (by god knows who) block that plug came out way too easy...
Thanks Again !!!
Gary

 

[Doug99RS]

Right again, Doug99... Pulled the seal and the spring was off. I'm guessing if you don't have that special tool you MUST oil the seal lip or it will "roll" the spring out like you said. If you check the bore with the seal out there's an edge where the bedplate meets the block, so some ATV is definitely in order, taking care not to block that hole at the 6'oclock in the bore... While back there replacing that little oil galley plug (shown on the diagram you posted, btw) seems like a good idea also, on my rebuilt (by god knows who) block that plug came out way too easy...
Thanks Again !!!
Gary

Glad you were able to find the problem. On that little plug... is it like a core plug that gets hammered in or is it screwed in? If it's screwed in then you'll want to put teflon tape or paste on the threads to help seal it.
Doug

 

[gspears3]

Put in OEM seal, still leaked. Bought Fel-Pro PTFE seal and the installation instructions said that some cranks had the bolt holes drilled all the way through the flange (this one does) and would leak through the bolt holes. It's got 8 holes and only 7 have bolts (still wondering about that) the 8th hole is threaded but appears to be a different thread from the others. So the oil is coming from the 8th hole. Will plug it or put in a bolt and use thread sealant on all. Neither the OEM or the Fel-Pro rubber seal instructions mentioned this issue, only the Fel-Pro PTFE. Live and Learn. Also, one of those $49.95 ATV jacks makes a great tranny jack and way cheaper... Again, thanks for all the help !!!
Gary
p.s. that oil galley plug behind the flywheel is the "tap in with hammer" kind and quite small. Drilled two holes in it and used a needle nose to pop it out so's not to lose it in the block. Figured I'd replace it while I was back there.