kel

Hi Gang,
I have an '88 RX with 140k miles. I was driving on a side road the other day when I saw a quick puff (small) of steam from under the hood. By the time I could get to the shoulder, the temp gauge was pegged.
I had the car towed home and thought I'd need to replace one of the radiator hoses. Imagine my surprise when I found that the plastic (!?!) part of the radiator had separated from the heat exchanger tubes. (the plastic appears to be attached by being pressed into some metal fingers - sheesh)
Anyway, I replaced the radiator, refilled coolant and started it up. It starts, but runs like some of the spark plug wires are disconnected. Very rough and NO power.
How do I tell if I blew the engine when it overheated? Up 'till now, it has run just fine.

TIA!

- kelly koop -

blackdragonsocal

hhmm, white smoke up on startup? If you overheated and destroyed your coolant seals then you'll see a bunch of white smoke when you start the motor. yes it'll need a rebuild. I'd also recommend you get a compression test. Not to bring you down, but from your description the situation sounds grim.

kel

Thanks for the quick reply. Actually, no smoke on startup or other. Just rough running and no power.
Do you know much about the Air Flow Meter?
I've been thinking, and reflecting back. I was trying to remove it (Air Flow Meter) and "disconnected" the control cable incorrectly and am sure I screwed it up. I have an '87 turbo model in the drive next to the '88 and removed the AFM. The model numbers were identical, so I put the unit from the turbo into the non turbo. Perhaps there is a difference that isn't reflected in the model number.
That's the only thing besides heat damage I can think of.

- k -

blackdragonsocal

I believe that the AFM's are identical (the Turbo II's use a boost sensor to measure boost) but I could be wrong.....definately get the compression check. Lumpy idle is usually a sure sign of a dead engine however with out a compression check it is possible that something else is wrong (i.e. vaccuum hose, gremlins, etc.)

SonicRaT

iTrader: (6)

The AFM's are interchangable. Did you notice anything else broken when you saw the radiator was ruined? You can try taking the leading spark plug out of the front rotor, turning it over and listening to the puffs, you should hear 3 even puffs, if so replace the plug and remove the rear leading and try again, you should hear 3 even puffs (best to have someone turn the car over while you're sitting with your head under the hood) Make sure you pull the EGI fuses before you attempt this, otherwise you'll shoot flames out the spark plug holes! Good luck, sounds like a bad situation though.

hypntyz7

You probably did hurt a coolant seal or an iron water jacket by getting it that hot. it doesnt take even that much to kill a rotary.

Pull both lower plugs and examine them for water. That will tell the story. THis is a reason it would run so rough with no power...one rotor is barely/not firing due to being flooded with water and the plug fouled.

GO out to it, crank it just a time or 2 to turn it over, then puill the plugs and look for water that may have been splashed around.

Hard starting is also an indication of this. The smoke comes in later stages of this problem.

The Ace

Checking if a rotary engine is dead is really quite simple:

1) Take apart the intake system (up to the turbo or intake manifold for N/A) and check that there is nothing wrong, i.e foreign objects, something broken etc....Re-assemble

2) Take off the two lower plugs (or upper, doesnt really matter), take off EGI fuse (first one from the left), and then have a friend crank the car while you hold your hand over one hole at the time. If you get even and nice, strong pulses ("puffs"), then your engine is fine compression-wise...If not... Re-assemble

3) Measure and test TPS, BAC and AFM (FSM has tests for all of these) damn, thats a lot of acronyms If all are within specs, re-assemble. Change anything that is malfuctioning. Check plugs and wires to make sure that they fire up correctly.

4) Take off radiator cap. Start up engine and let it idle until it warms up. Fill up with coolant as necessary. Check for bubbles in the filler neck or in the overflow tank after the thermostat has opened. Bubbles mean that water seals are gone (or are starting to go the dodo way....) If you dont see bubbles, you still should check coolant for exhaust gases. It could be a very minor problem (which will develop in a more serious problem). You can still remedy this with some radiator sealant.

By now, you should have found out what's wrong. If not, then only an experienced rotary mechanic can figure it out.

EDIT: Something that I forgot:

5) Even if all the above are fine, the engine may be still consuming oil, coolant or gas completely out of specs. You could still see white, blue or black smoke coming out of the exhaust. Black smoke is usually the easiest to fix (rich). Blue smoke means oil, and if its not too much, you can live with it (just fill up with oil more often). If its white (and lots of it, so its not just condensation), then you should probably check for coolant leaks.

6) All the above check out fine, and still the engine has problems ? Well, what did you think ? The wankel is an engine, not a can-opener Get an experienced mechanic to check it out











Damn, that was good info. Everybody rate this so it gets archived

hypntyz7

Good writeup ace. Im too lazy for that these days. I have delegated that duty to others

The only thing I would add, is to do #2 first, then #4 I think, then the others. save #1 for last, its the hardest...

lol