asherwood

My car was in the body shop to have some minor door work and paint, when the shop phoned and said " It's kind of idling funny now, you better come down a listen to it..."

Well, my trusted rotary mechanic now tells me that 2 of the 3 apex seals on one of the rotors are no longer functioning! I've seen the tape produced by the Mazda compression tester on sure enough nice set of three blips for one rotor and basically single blips representing the output from the second rotor.

Leaving for a moment who may be liable for the repairs, the engine has only 77K kms, should I just have the seals replaced (assuming no other damage), look for engine from another car, get a J-spec engine or pay the big bucks and buy a factory 13b (if they are still available)?

Depending on what the mechanic finds after opening up the engine will determine who pays the final bill, the bodyshop if they can be proved at fault or me if the failure was not caused by negligence on the part of the bodyshop.

Opinions and observations on how to proceed and what to look for would be greatly appreciated...Thanks

rx7_ragtop

Ok... first, I don't think I would trust that "rotary mechanic" if he doesn't understand that 1 bad apex seal would affect 2 of the 3 rotar faces.

2nd, it's rebuild time. You won't know how much damage is done until you get into the motor, but you PROBABLY will need at least 1 rotor housing. Don't try to skimp on replacing apex seals, do a full rebuild.

Brad

asherwood

Brad,

I'll have to clarify exactly what he said, I do trust him as he has a good reputation and has done extensive work on 1st, 2cd and 3rd generation cars. He did say that the total extent of the damage would only be evident when the engine is apart.

The tape produced by the Mazda compression tester shows a full pulse followed by a partial pulse then none. Of course this pattern repeats. The good rotor shows 3 fairly similiar pulses.

Any thoughts about other work that should be done while the engine is apart for the rebuild that would improve reliabilty and some amount of performance?

hawk 7

iTrader: (2)

How is your mechanic going to determine who is responsible for the repairs??

Ni5mo180SX

just wondering but do you think it might have been mistreated while at the body shop?

RETed

You can nitpick about the details on the compression test results, but bottom line is that the engine needs to be rebuilt or replaced...


-Ted

asherwood

A couple of points: 1) running like a top before they drove it 2) 3.5kms of unaccounted for milage.

Just waiting for the insurance adjuster to call back...

CrackHeadMel

iTrader: (2)

Ohh buddy, if it turns out they fucked with your car, take em for all there worth

Grizzly

U should always record your milage before it goes in and warn them not to rev when cold, Then you can f**k them over if it does go. But they will turn round and say they have done nothing to damage the car and u cant prove they have?

I work in a Body shop and u tend to find there stop started alot (never let warm up). the thing is Body shops dont usaly mistreat cars whilst booked in for this reason (agro when somthings damaged or broken). As i say i work in a Large (Honist) Body shop and you will be suprised how many people try to get Free work done by complaining that we had damaged there car, it got to the point where we had to check them when they came in for damage.

asherwood

Grizzly, I hear you about people looking for free work. In this case I would be have been only too happy to have an 'uneventful' repair action... It was bad enough that the door needed to be repaired and painted, but you can imagine my feeling when they called 4 days later with no work yet done on the body repairs and tell me that the engine is not running right! I thought that I was going to puke!

The milage issue is kind of unique, I wasn't planning on recording the milage but a couple of blocks from home on the way to the bodyshop the odometer turned over to 77,777km! The car now has 77,787km a difference of 10km. The trip from home to the bodyshop and then to the mechanics shop where the car is now adds up to 6.5km, hence the unaccounted for total of 3.5km. And I also have a witness that saw the car be driven around town a day after it was dropped off at the bodyshop.

A recent call from the insurance company still leaves me with proving that the bodyshop caused the damage to the engine. The insurance adjuster commented that other's in the department believe that rotary engines are weak and prone to sudden unexplained failure!

So like in a court of law the bodyshop is innocent until proven guilty!

autocrash

Well, uhmm... yeah, you ARE dealing with the law here... would you expect anything less for yourself?

btw, if they did it, take 'em for what its worth!

BKC TURBO

Yeah, all that sounds serious, but how serious won't be known until someone gets into the engine, as someone stated earlier. Looks like a total rebuild to me, and nothing short of that. I don't know how you would prove that they ruined it, but you did say someone saw the car being driven after you dropped it off. And I don't know that a road test is part of body work. Start there.

asherwood

Well I have the car home tonight, I can't afford to have the shop tear into the engine right now (no cash )

But in further conversation with the mechanic he suggested that there may be one other thing to try, he noticed that the plugs (about 1 year old) were heavily carboned, his thought that the apex seals could be caked in carbon...

What about pouring a bunch of combustion chamber cleaner down the sucker to desolve all of the deposts? You know, the ATF trick.

Maybe, the only problem is a stuck apex seal?

Worth a try?

AggieDave

maybe i dont know what i am talking about.. but think about this.....

how can a piece of metal... that is springed against a rotor housing, where it is making a friction contact, develop carbon that will cause the combustion chamber not to seal?


ps... if 2 apex seals are bad then there would be no compression on the rotor.. as you need 2 good ones to have 1 good chamber

dave
87 TII (Series V Conversion)

asherwood

This was what I was thinking Dave, There is only one apex seal in a "non working" state. This seal would affect 2 chambers and this is why the compression tester shows only one pulse. A piece of carbon was disslodged and found it's way under that one seal and is now preventing it from doing it's job.

A couple of months ago I used MMO in the tank and in the oil, maybe this is a result of this process?

AggieDave

to get under an apex seal you need to either 1) break it or 2) go through the tiny tolerances between the plates and over the side seal, and happen to make it through the rubber stopper on the hole in the corner seal.

ie... not good odds


i think the seal is bad.....


my .02

dave
87 TII (Series V Conversion)

asherwood

Could carbon eventually gum/stick the seal into it's slot so that it doesn't maintain contact with the housing?

And would trying to 'de-carbon' the chambers do further damage? Or am I prolonging the enevitable, a tear down?

AggieDave

if you have ever taken apex seals out of a rotor you can see that they are tight.. getting gum around them, if at all possible, would not cause a problem until it hindered the spring below. no likely

sorry, but i think you are prolonging a rebuild. but dump some atf in there.. couldnt hurt. especiall if the seal is gone


dave
87 TII (Series V Conversion)

AggieDave

if "gum/carbon" got under the apex seals... 1) there would be a design flaw and 2) you would hear about it mor often

dave
87 TII (Series V Conversion)