Bought my first Mazda today - a 1990 B2600i 4x4 with 150k on the clock, that I was excited about.
Truck ran well on my 4 mile drive home but when I stopped, smoke started pouring out from under the hood.
Opened it to realize oil had been spewing out and was burning on the exhaust components. Pic below.

Fresh oil seems to be coming from somewhere under right under the distributor and coating the water pump and everything below?
Valve cover and oil filler cap look fine. Fan and belts are clean.
Oil level is good in the pan, and looks good on the dipstick...not foamy or milky.

NOW for the kicker:
Temp gauge on the way home read cold.
When I went to check the radiator fluid just now, it was *bone* dry.
When I filled it, it came right out of a freeze plug hole where one was missing

Looking forward to participating in the forum!
Would really appreciate some help here.

 

If oil is actually coming from the distributor: the distributor will have an O-ring/seal on its shaft; either mark the position real well before removing it, or know how to do its ignition timing. There will also be an internal distributor seal, but once you remove the distributor you should be able to tell if that is the source of the leak.


Well, now you know the source of the leak !!! Install a new freeze plug.

 

Yessir. replaced two blown freeze plugs with the rubber expansion ones. Filled it with water, and the water pump is leaking badly.

There appears to be a little *crack* in the very very top of the water pump; right under the distributor where it mates with the block.
Curious if is there *any way* this could be the source of an oil leak?

Ordered a new pump and a bunch of other tune up parts today. Do I need some kind of special 'water pump wrench' to do this one?

 

Got the fan and water pump and radiator out of the way and now have a very clear view: The timing chain cover has about a 3-inch crack running through it, below where it mates with the head. (See pic).
I wonder what caused this and am afraid JB Weld won't solve it.
Looking for a used timing cover now.
Can anyone describe what's involved in replacing the timing cover on a 4WD 2600i?
It appears to require removal of oil pan, valve cover gasket, and a few head bolts!!!???





Timing Cover crack running left-to-right near top of image

 

Wow. Hope you got a good deal on this truck. Pretty f**ked anyone would sell it to you this way.

Timing cover removal on these is a bee-atch. Mazda had the brilliant idea of making the oil pump (and it's pipe and pickup) an 'integral' part of the front cover. So it won't come off unless you first drop the oil pan. To do that (on my 2WD), I had to remove the frame brace under the pan, as well as the center link (the big rod that goes between the two sides). To do THAT, you also have to break the center link loose from the Pitman arm and idler arm. The quick way to do this is with a picklefork, but that will rip the rubber dust coves on the bearings and you'll have to replace them. If those bearing are okay (mine were), you can get them off with a bearing puller made specifically for ball joints, but it will also require more than the usual amount of cussing and bloodletting.

Once all that's done and the pan is off, it will become obvious why you have to do it this way.

When I redid the head gasket on my '92 "i", I went ahead and bought a whole gasket set, as well as water pump. I had an oil leak out of front seal (in the front cover) and the pan, so figured I'd just take care of all of it.

I may be coming in way late on this response and maybe you've dealt with this already. If not, I actually do have a good front cover. Let me know if you're still looking for one.

 

Whoah. Thanks so much for the reply John.
My guess is my 4WD is even more crowded than yours. Dang! I can't *fathom* that design.
Is there no way to just unbolt the front-most 2 rows of oil pan bolts that are bolted up into the timing cover, and then once all the timing cover front face bolts are out, it could just lean forward and lift out? Without dropping the whole pan?

Do you also have to pull the valve cover and everything on top of it? From the way the timing cover is shaped, it appears that there are two bolts going down through the head and into the timing cover...
I was *guessing* that the reason the timing cover might be cracked where it is could be due to someone overtightening those front two head bolts.
I saw on the Service Manual (screenshot below) that the front two are indicated as "A" bolts that only get 1/5th the torque that the other head bolts do. Maybe Prior Owner had a head gasket done or something, and the shop cranked down on them?

 

Lee,
I don't know how to post pics, but go here: https://www.streetsource.com/threads...ing-chain-help

And look at the pics about halfway down showing the motor with the pan removed. You can see the oil pickup tube and how it's attached to the front cover.

So in other words, even after you take off all the bolts going through the front cover, the two coming down from the head, and the few little ones in the oil pan - AND you take off all the various brackets, distributor and alternator (after removing the power steering and AC pumps from their brackets), the front cover will still not come off - because there's one more bolt that holds the tube to the block that you can ONLY access with the pan removed.

From looking at the last photos you posted, it looks like that means the front differential would have to come out of your 4X4. Yikes.

At this point, I think you have only two options: 1) Try to get your money back from this crook that sold you this truck, or 2) If you really, really like the truck and want to save it, you will have to pull the motor to do all this stuff to it. Big job, big pain, and big time commitment. But once you get it out and on a stand, the actual repair stuff would be super easy.

If it were me, and I had the bucks, personally I'd replace that motor with a JDM unit. This stands for Japanese Domestic Market, and basically they're about 50,000 mile engines imported from Japan. Last time I checked, a Mazda G6 engine (B2600i) sold for about $800. You would need to purchase a gasket set because you'd need to swap the manifolds and a few odds and ends from your engine onto the JDM one (becuase of different smog hookups there and here), but you would NOT have to pull the pan, the timing cover, the head or hardly anything else. And when you put that engine back in and fire it up, you will essentially have a 'just broken in' motor that, if you take care of it, will last you a long time.

And yes, I think the cracked timing cover is due to some bozo overtightening the bolts that go through the head into the timing cover because he has never heard of torque specs and thinks all bolts should be tightened as hard as possible.

Good luck. Let us know how it goes.

 

Thanks so much for that insight and thread link- I grabbed an image from it, and thought I'd post it here for anyone else that comes here lookin' for answers. You're saying the whole pan has to come off in order to access the bolts at the yellow arrow which go into the timing cover? Or is it better to remove the bolt at the red arrow to pull the whole pickup tube up with the timing cover?

The JDM engine idea is an enticing one, but I just can't throw that much more money at this truck now; I was hoping that mine was still 'young' at 149k. You're saying pulling the engine to access the oil pan would ultimately be easier than trying to do it on the truck and having to deal with the center link and differential? I was thinking at least the differential is *behind* that bulge where the oil pan drain plug is; thought differential might be okay staying put because assumed once pan bolts are removed, pan would slide out towards front of vehicle?

I only discovered the source of the leak after hitting the engine with a pressure washer my neighbor loaned me - It seems PO had wiped gasket maker all around the crack in an attempt to seal or disguise it. Now that I understand what a bear of a process repair would be, I'm rethinking the JB Weld idea . I once had good luck stopping a crack in an oil pan with JB Welds "Marine" product, as it's advertised as being resistant to oil & gas. Am I right that this crack at least isn't under pressure and so I might get away with sealing it? I was thinking maybe that process would be to 1) pull the valve cover and loosen those two "A" bolts completely to relieve tension, 2) spray down the cracked area multiple times with brake cleaner, 3) sand the area to promote adhesion 4) apply the JB Weld and push it into the crack as much as possible, 5) tighten the "A" bolts to correct torque, 6) let it sit for a day to let the JB Weld cure.

 

I removed the 'red' bolt and took the timing cover and oil pickup out as a unit. I guess you could remove the 'yellow' bolts - but again, you'd still have to drop the pan to do it.

JB Weld could work. I'd just use the 'original' stuff. About a billion years ago I had a '67 Firebird with the 326 that somehow eroded through the timing cover and started leaking coolant. So that cover was shot. Went to several wrecking yards but couldn't find a replacement. As I'm walking out of the last one, I see a portion of a timing cover sticking out of the mud. I pull it out and shake some dirt off and - holy moly - it's the right one! What are the chances? Only thing is it has a crack, probably from being run over by a forklift or somethign because it's right where you come into the yard. Anyway, the guy watched me do it and he just laughs when ask how much: "If you think it will work, just take it." LOL

So long story short, I take it home, clean it up really good and JB weld the crack. Had the car for many more years and it never once leaked (at least from the timing cover). So yes, I would do what you're suggesting and see if it works. Certainly nothing to lose.

To answer your other question, there is no pressure going on directly behind the timing cover. As I recall, there's some kind of oil sprayer or slinger or something in there that keeps the timing chains lubed. (That's where the oil is coming from thats leaking out.) If your patch holds, I'd say you're good to go. Hope the rest of the motor is good. And yeah, 150K isn't all that much if the engine has been cared for.

One more thing: That top bolt that goes into the cracked part? When you put that back in I would do it a bit below torque spec. I don't think it does a lot beyond keep the head gasket sealed against the timing cover. Slather it in threadlocker first. The other one can go in at spec. Again, good luck and let us know if it holds!

 

Hey! That's my motor in those pics on the Street Source site!

Yep, the oil pan will need to be dropped in order to pull the timing cover, which is actually the oil pump also, if you buy one.