Winndixie managerman

Subject says it all. Just found out I have large amounts of oil in the coolant lines and that the engine is toast. I was wondering if anybody would have some advice on finding a new 12a motor or possibly a way to repair my existing one. Any help is appreciated.

gsl-se addict

iTrader: (3)

Are you absolutely sure the engine is dead? What are the symptoms? The 12A '85 (what you have by your profile) has that oil-water 'beehive' oil cooler. Maybe there is a crack in it that let oil into the coolant.

How many miles on the engine? That may give some idea as well as what failed would at least give an idea of what you would need if you did the rebuild. Are you planning to keep this car for a long time? How much could you afford to put into the rebuild? We neeed to know stuff like that so we know if you would need to do the rebuild yourself, get a junkyard motor, get a budget rebuild, or a full blown rebuild (nearly all new parts). Good luck. Sorry if the engine is toast.

Kent

Winndixie managerman

Okay, my car is a 85 with a 12a and it has about 192,000 miles on it. The car is still running but performance has dropped sharply in the last few weeks so i took it to the shop and told me the wonderful news. I wish to keep this car but I don't have a lot of money to spend on a rebuild. So that's that.

gsl-se addict

iTrader: (3)

^ Good one Turbo.

Are you sure you can trust the shop? Usually rotaries don't get oil into the coolant like that. Did he say it was a blown coolant seal or was it an apex seal? Did he check compression (with a Mazda tester)? I suppose if you had a bad coolant seal, maybe oil in the combustion chamber would get in? Is there any smoke, or overheating? Does the coolant get pushed into the overflow reservior just after starting?

How mechanically inclined are you? If it is blown, probably the cheapest/easiest option would be to get a used engine off someone on the fourm. This is a gamble, but may work well for many years. It isn't too hard to swap engines. Just basic tools and a 'cherry picker' and you'll be set. You could probably find local rotorhead to help out. You could rebuild yourself or get a rebuild from Atkins, Mazdatrix, or wherever. Lots of options. Good luck.

Kent

Winndixie managerman

Actually it was a leak from the hoses that prompted me to take it to the shop and they found oil in the coolant lines they thought were broken.

TurboSE

yah like kent said ......Make sure the motor is not blown....and if it is try to get a used one......i just sold one 4 $200 good compression and all
theres a guy selling another one for $150 but he is here in cali=(

gsl-se addict

iTrader: (3)

So you had a leak (oil?), took it to a shop, and they found oil in the coolant lines. Is that it? Did they say it was blown just because of that? That doesn't sound right. Maybe the power loss is something else.

A coolant seal wouldn't hurt power much. You would likely get white smoke, pressurized coolant system, having to refill coolant constantly, etc. A blown apex seal will totally kill power. When mine blew on my SA, it would only do about 55 mph WOT, and probably took 1 minute to get up to that speed. I didn't have smoke or oil in coolant. I still think the oil is coming from the oil cooler. The only way it would come from the engine is either a cracked housing or oil coming from combustion chamber though a blown coolant seal (but you would have at least some of the other sypmtoms I stated above). If it was a cracked housing, I would expect to see coolant in the oil as well.

Winndixie managerman

Mostly i am having problems with the coolant light coming on. The oil light hasn't come on though. No smoke, no major power loss but the car has has more problems with starting, like to mix it getting more and more off. To that extent, the car seems to running rich, and I don't think the carb is all to blame. Any suggestions?

TurboSE

is the car overheating?
i would try the Block weld? stuff (treatment) drain your cooling system and stuff
i'll try to find the link

TurboSE

https://www.rx7club.com/showthread.p...ock+weld+trick

Winndixie managerman

other than the coolant light, the car has been running within normal tolerances excpet for the slightly sluggish response and the rich mixture. The car was leaking coolant from the lines and not oil. Could a leaking water pump or something of that nature cause this? Thanks for the link btw.

gsl-se addict

iTrader: (3)

So the coolant level is going down? Have you been topping off the coolant when the light comes on? Is the coolant temp in the normal range? What did the shop say was the reason the engine was bad?

With the engine cold, you can take the rad cap off and fire it up for a minute. If you had a bad coolant seal, the coolant will probably overflow right away. If it is a small breach, you will see small 'champagne' bubbles rising up in the rad. On the 12As, a common cause for loss of coolant is the o-rings in the manifold. Mazda routes coolant into and out of the manifold to warm it up. When these go bad, the coolant gets into the combustion chamber. This will produce white smoke and a loss of coolant, but not the pressurized coolant system and overheating a blown coolant seal may create.

This may explain the hard to start part, but not the oil in the coolant or the fact that you aren't getting smoke.

If the shop can't substantiate the reason for the engine being bad, I would try to at least get a second opinion from another shop (don't tell them what you think is wrong, just tell them you are buying th car and want it checked). You could maybe find a local guy of this site that could give you a hand as well.

I would try to get an SE oil cooler (or mod a S1/S2 cooler or 2nd gen cooler to fit). This would at least eliminate a possible source for the oil in coolant situation. They also work better than the beehives anyway.

Flush out old coolant and replace. This way you can see if the probalem continues.

Change oil. See if there is any coolant mixed in with it.

After sitting overnight or a couple days, disconnect the spark plug wires and crank over for a couple seconds. Pull out the spark plugs. Do thet have coolant on them?

Good luck with it. If you have any questions, just ask. I personally don't trust any shops, especially when it comes to rotaries. You do have quite a few miles on the car. Has the engine been rebuilt before?

Kent

gsl-se addict

iTrader: (3)

Well, if it was coolant that was leaking, that would explain why the coolant light is coming on. I would still try to install a front mount oil cooler. It will get rid of those extra coolant lines and reduce the chance of oil getting in the coolant. If you don't want to do that, replace all of the coolant lines, replace the o-rings in the beehive, and maybe pick up a different beehive from someone (just in case yours is cracked). I don't think you need that block weld trick as you are not getting white smoke, and aren't even sure if coolant is getting in the combustion chamber.

Winndixie managerman

yes i have been topping it off every morning before i went to work the leak was pretty bad.

jason_child

try the intake manifold o rings

Winndixie managerman

Thank you to everyone who contributed useful information to this thread. What was provided has led me to believe that perhaps my motor can be saved. However if anyone has another opinion that is worthwhile please feel free to post it, I would greatly appreciate it.

slashdawg00110

I don't have much to add other than if you put a front-mount cooler in there, use a FC cooler rather than a -SE cooler. The -SE coolers tend to have or develop cracks in the fittings the hose ends go into.

Let us know how things work out.

Winndixie managerman

Well, finally got the car back from the mechanic and he eloborated on what he had found. He said that when he had yanked the hoses a large amount of oil had spilt out, along with coolant. He refilled my radiator and sent me on my way with a 100 dollar labor bill. Anyway, when I was pulling out of the parking lot my oil light flicked on, so its moving oil pretty quick. The only thing that I can figure is that a coolant seal must have gone because the oil pressure is stable and pushing the oil into the coolant system. By the way, does anybody know where I can get a good rebuilt or new 12a engine for under 1600 dollars? (I'm poor, really poor)

gsl-se addict

iTrader: (3)

When you left, had he topped off the oil first? Maybe the system was low to begin with. If you were to lose that much poil into the coolant system, there should be lots of oil in the rad and probably the overflow reservior as well. Thinks about it. You would have had to push out 2 quarts or so in that short of a period. If it went into the coolant, the oil would displace that volume of coolant, so now the coolant system (~10 quart capacity) now has 2 more quarts of fluid in it (the oil). The excess would have to be pushed out the overflow.

Go ahead and top off the oil. Start it up, check for leaks. The shop may not have tightened down a fitting (causing the oil loss) or there wasn't that much oil in the system to begin with. If you don't see any leaks, take it for a short drive, check oil again. If it doesn't go down, continue to drive it, but keep an eye on the oil. I still don't believe your engine is bad. This type of failure just doesn't happen (unless highly boosted application [cracked rear plate]).

Rogue_Wulff

Sure sounds like a bad "beehive" oil cooler to me. That is about the only place oil could be entering the coolant, and not getting coolant into the combustion chambers.
The beehive coolers have both oil and coolant in them. Coolant pressure is 17PSI tops, while oil pressure is 30-60PSI on a decent engine.
I would try pulling the beehive, and having it tested at a local radiator shop, before deciding to replace the engine.

Winndixie managerman

My oil psi when driving hovers around 65.... is that indicitive of something being wrong?

Rogue_Wulff

Not at all, that is where it should be. Most likely the beehive has either a crack, or a small hole rusted thru, that is allowing oil to enter the coolant.

Winndixie managerman

Finally took a looksee today... the cooler seems to be okay but it is leaking oil like a mother. Looked in to radiator reserve resivior and it was black with oil ugh. Tried to see how to replace it in the haynes manual but it only covers when the cooler was placed under the radiator. You guys know where i can find instructions on how to remove and install the cooler and its seals?

trochoid

iTrader: (6)

There are 2 nuts and 1 bolt that hodl the entire unit to the block. Then there are 2 nuts that hold the cooler to the pedistal. You also have to remove the cooling lines and the oil hard line. Do not bend the hard line and replace the crush rings. There are 4 o-rings total in the oil cooler. The 2 that fit in the depressions shown and 2 more between the pedistal and cooler.

Below are pics of the bottom of the cooler. It should be self explanitory.

When oil mixes with water, it usually foams, at least in the oil pan.(It may not in a pressurized cooling system) Smell your coolant, does it smell like oil or something else?

gsl-se addict

iTrader: (3)

I bet it is the oil cooler. You should pull it off and replace. See if you can get an air-oil oil cooler (GSL-SE, 2nd gen, '82 and earlier first gens). The SE one is a direct bolt in. The others may require a little modification to the mounts. After you swap the oil cooler, flush the coolant system good and refill. Hopefully that will take care of your problem.