Miles on Motor - Question
 

Ok looking for an FD. Should anything over 75K on the stock motor throw up a red flag? I ask this because I don't want to buy an FD then have to rebuild the motor shortly there after.

Thanks

The compression test will give you some idea, but many, many stock motors give up the ghost at 75k due to coolant seals. Most original motors never see 100k. So scout it out thoroughly for any signs of coolant seal trouble.

Dave

^+1..I'd make sure to do a compression test,but regardless of the results I would still be uneasy about buying a car with a 75k motor..If I did purchase it,I would make sure the seller takes off a good chunk of his price for the possibility of a rebuild very soon.

My thoughts exactly. Thanks guys

A rebuild is almost inevitable with a 75K motor. It literally could fail in less than another thousand miles, or it could go as many as 125,000 miles. Problem is if you tie up ALL your funds simply purchasing the car, you may not have enough left over for mechanical issues.

Asking the seller to reduce the price is unrealistic in my opinion, unless he is WAY high or towards the high end of current "street value" (read: NOT Blue Book). I mean, if the car is sound right now, why would he drop the price?

In the end, this is simply one of THE most definitive issues that separates the FD from other used cars. You simply HAVE to expect a rebuild. Compared to a Honda or Toyota that you could buy with 75K on it and feel it was hardly "broken in yet", a high mileage FD is a ticking time bomb. This alone is why I feel SO sorry to see some young kid get his "dream car" when he/she is on a limited budget. There is no worse feeling in car ownership than having a broken car sitting dead while you are trying to save money to fix it, and having to go thru the hassle of borrowing cars and enduring the ridicule of friends and family about your broken car.

Welcome to my life ;) Except I was lucky enough to have people lend me money in order to get things fixed..But then you get ridiculed for "owing them money" lol

^^ very true.

I spoke with the seller and he wants 16,500 for it. All stock except cat back exhaust.

I did mention that that motors life span is 75-100k. He said he did not know how long a rotary last but it runs good.

man, I have wanted a FD for the 10 years I have been into rx7's.
One day I will get one and will sit in the garage next to my 77 repu, my 85 gsl-se, and my 79sa/gsl/TII.

Is there also 75k on the chassis?

He could be telling the truth - many FD owners don't know anything beyond their own experience.

Then again, it could have bad coolant seals, and he put in block seal and is immediately selling it. And playing a little dumb. That person will find an unsuspecting buyer and that buyer will have it fall apart within the year. Sad, but true.

Dave

Regardless,$16,500 is way too much for an FD with no mods and the motor on its way out,imo..Unless that car has a showroom paintjob and the interior is a 10/10,I wouldn't even consider it..

Yes

With some exceptions (a 20B or LS1, for example) mods add no value to a car - and stock FDs are generally much easier to sell. I'd much prefer a stock car with 75k miles. Blue book excellent condition is close to $17k for this car, so if the condition is very good, the price is about right.

It is unrealistic to expect the seller to reduce the price for a potential future engine failure. The price of FDs already reflects this possibility - if FDs had bullet proof engines, they would probably be selling closer to the price of Supras.

I get sick evrytime I read one of these posts. Partly because my car has 72K miles on it! There are several posts about guys getting well over 100K out of their motors.
Here is one of those posts.

https://www.rx7club.com/showthread.p...ighlight=miles

Not sure why the FDs are known for blowing so quickly. I got over 169K out of my 88 Turbo II. The only reason it blew was because I ran too much boost through it. If I wasn't so dumb, it probably would have lasted much longer.

I would say that as long as you do proper maintenance and supply the proper amount of fuel for the amount of boost you are running (within reason) the motor will last well over 100K. Obviously, you will also want to do everything possible to avoid an overheat situation which seems to be the demise of most of these motors for some reason.

To avoid an overheat situation, upgrade the AST to a metal unit, change your coolant when needed, and watch the temp gauge.

If you are smart, do a compression check on any FD you plan to buy before you buy it. This will give you the best idea as to how much wear is on the motor regardless of mileage.

And 4578354 posts from people who have just blown their engines with 50-80k miles.

Not being a smart arse, but FDs are known for blowing their engines so quickly because, well, they blow their engines so quickly.

This is wishful thinking. Apart from a subgroup of people who buy these cars cheaply and can't really afford to maintain them, FD owners are a actually pretty anal lot and do do all the proper maintenance procedures, and monitor air fuel ratios and coolant temperature compulsively. How many other cars have such a high percentage of permanently wired wideband oxygen sensors, for example? Yet even with all these precautions, 100k engines are rare.

With 70k+ miles, I'd put aside $100-$200 per month so that when it does blow, you are ready for it.

Your reading comprehension is the problem. I said "most". Out of the hundreds of FD owners who have posted on this forum, the fact that "several" have made it past 100k is a pretty good agreement.

If you're going to get sick of something, find a point.

T2s run lower boost.

Dave

Ok, if I do buy this or another FD with that many miles it will have to be cheap enough for me to pull the motor and build it. I don't plan on any serious HP numbers anyhow, just want 300-350 and for it to be reliable.

As for the motors blowing, most FD owners have gone thru it at some time before 100k. I am sure that the carbon build up on most of the FD's that were driven buy big rich men that never took them past 3500-4000 rpm's did not help.

As for the TII motor, well I have owned 4 TII's and two of them had over 115k on them on the stock motor but the TII is a bit different.

As with any rotory, a header, intake, and good exhaust with out any other mods done for fuel or boost is not good. This is the one thing alot of rotary owners do with out knowing what will happen.

Anyhow, I am probally not gonna get that FD as it has the red interior I do not like, and with those miles and the asking price I say it is a bit too much to spend.

Thanks for all the feed back guys. I know alot about rotary motors, building them, and what not, but I never owned or worked on an FD so I thought Iwould get your opinon's.

Thanks again.

The heart of the issue is that most FDs have already suffered "fatal wounds" at the hands of their initial owners due to the overall ignorance of the FD by everyone in general and specifically by dealer's mechanics. And quite often these walking-wounded FDs show no outward signs of their imminent demise until, well...they die.
How the hell is someone buying a 11 to 14 year old car going to KNOW that it has never been overheated, or overboosted, or leaned out, or had anything CLOSE to required maintenance done on it?
Now on the other hand, an FD that has been owned by someone who has replaced the engine and done all the reliability mods and understands the car would be a MUCH safer bet for a high-mileage purchase. I know I would be much less hesitant to buy a car that had 75K on a rebuild that was properly taken care of than on an original engined car of unknown history.

If you keep the FD mildly modded (around 300 rwhp or so), it's going to have a pretty good chance of making it to 100k miles if you perform the required maintenance and everything in the engine bay is in good shape. My dad's R1 is set up like this, and he's going on 50k miles with no problems. At that power level, his FD is fast enough to pull on C5 vettes and M3s, not exactly a slow car.

If you mod your car out the wazoo to get to over 400 rwhp on pump gas, you can't expect the motor to be in the same league as a toyota or honda engine. You've got to pay to play.

Thanks, that is what I am thinking. I really want that silver fd dewayne is selling in NY and get that front bumper you have on your FD, tint the windows and add a spolier.
That would be one sharp Fd.

Chad, just keep looking and wait for that good deal to fall in your lap. I just picked up a silver FD for a reasonable price. It has the red interior too, but I must say, it has grown on me over the years. I use to hate it.

couple things.

1. as with anything else, the majority of the engine failures occur between 70-90k miles. thats what you should expect. there are some that went far less, and some (like mine) that have gone further.

2. we know the majority of the engine failures of the FACTORY engines are coolant seals. and you guys are telling him to get a compression test. a compression test basically is telling you the helth of the compression seals right now. it tells you NOTHING about the coolant seals.

3. the fd is like everyother car, it needs periodic maintenance, and being a mazda, you can put it off for a long long time, for the most part, but the engine is on the list of things that need to come apart periodically, like the rear suspension pillow balls, etc etc. actually i'm thinking about it, once you do the updates to a stock car you really dont have to touch it again, for the most part.

i'm not really the fd guy, but my friend does nothing but work on these things, and he paid off his house building engines, and now he's broke cause they dont break anymore....

Could be worse.. could be me! I bought a broken one with the funds to purchase an extra engine on tap. got that and tore the engine bay apart.... the whole time finding MORE and MORE that I wanted to replace since I was already in there.

So my 1 month project has turned into a 1 year endeavor. could take longer... but by golly I hope not.


Long story short, calculate how much it is going to cost you to fix it if it breaks. double that number. add in time spent and free time available. If you do not have flexible funds available, then an FD is not the right car at this point in life. It would be a financial risk. Or a very depressing/expensive garage/driveway ornament.

Here is my calculations:

The formula for an FD restoration is as follows (By Nathan Monk):

X = [H2-P] (must be positive number, or project will end up incomplete and sold as is

(FD*L) = [X((C1-((M2-PFD)+(H1/T1)))+(T2*M1))/ (C2/((H2+T3)P))]/L

Terms:
FD = Finished Project
PFD = Project FD that you get for cheap
T1 = Time (free time to work on the car)
T2 = Time (in relation to calendar time)
T3 = Time (in relation to how much longer it will actually take)
M1 = Money (used in relation to T2 to account for additional funds becoming available over time))
M2 = Money (in respect to initial investment)
H1 = Heart/Desire (to start)
H2 = Heart/Desire (to finish)
P = Persistence/Patience (to keep going when 20 things piss you off or you find yet another thing you want to replace for sake of perfection/reliability... or because it is easy now, but tons more work later)
C1 = Overall Expected Cost
C2 = Overall Actual Cost
L = How much You will Love your RX7 when finished