bdogg

I just picked up a 94 rx-7 with 62K miles thinking it had been rebuilt(new belt, looked extremely clean, drove fine,etc). To my horror, my local mechanic who has worked on 3rd gens since they came out ran a pressure test that showed 4.5-5.5 readings and suggests that something is probably about to give with the engine and that a total rebuild is in my near future. I simply cannot afford the $2300-2800 estimate that he quoted me to have it rebuilt right now. It may be several more months before I could save that kind of dough. What preventative maintenance or reliability modifications that would be relatively inexpensive could I do right now to buy my engine a few months time till I can afford the rebuild? The car is completely stock right now. Would a downpipe help? Any suggestions from those with a lot of experience with this car would be most appreciated.

Rehanke

Only drive it if absolutely necessary. No boost and keep the rpm's low. If you do an overhaul before the engine lets go you might not totally destroy your engine and you could save yourself some money if the internals aern't shot. If you wait until it pops then you'll run the risk of messing up your rotors, housings, and side housings.

-Destin

BustedRX

At this point theres really not much you can do to truly prevent it. A downpipe certainly wouldnt hurt. Your best bet though, at least as I understand it, would be to just give it as little boost as possible. Try to keep it under 3k rpms whenever possible. Just keep in mind that a rebuild is inevitable and continued driving only increases the chance of a more costly rebuild and possibly the rebuild of turbos if an apex seal decides to go.

Your fortunate enough to have identified the problem before losing the motor, Id say park it and save some money for a rebuild, theres a good chance you'll end up spending more if you dont.

teamstealth

Step one when buying a car- Take it to a mechanic and make sure EVERYTHING is in good working order....that was ur first mistake right there, not getting that compression test done before u shelled out the money to buy the car.

Theres not much u can do for a engine with low compression...it will go when it wants to. Basically drive it only when necessary and baby it...you dont want to boost it when u know theres faulty seals in there. I'm with Rehanke on this one...rebuild it before it blows, because then you dont run as high of a risk of destroying additional parts and can *probably* get away with just a rebuild seal kit.

-Zach

bdogg

The person has a good reputation but I must admit it seems a bit high. Is the rx-7 going to be really expensive to maintain with respect to other items?

BustedRX

You were a bit vague about the pricing. If its 2300-2800 installed, thats an excellent deal, assuming the mechanic knows what he is doing. Rebuilds alone can fall into that price range, or much higher depending what else is being done to the engine while its broken apart. A mazda remanufactured engine can be purchased for 1900-2200, depending where you look. Ive heard Malloy Mazda has good deals and great customer service.

teamstealth

well....Call Malloy Mazda and talk to Ray Crowe about a mazda reman motor and then compare prices (1-888-533-3400). Once you take care of the reliability modifications, maintanence shouldnt be too big of a deal...but be prepared for it to eat into ur pockets at times.

cpa7man

iTrader: (2)

I've heard of low compression engines lasting a long time. One day it just won't start. Keep driving it until then. I would not baby it as much as stated above. Why even have it if you don't boost. My car is running mid 6's in compression and I still drive it hard. Your going to need a reman anyway, the main risk your running is to ruin your turbos if metal shavings get in the oil.

Run some synthetic 2-cycle oil in the gas. It will help a little bit. Run it between 100-200 to 1.

bdogg

You use synthetic? I've heard so many differing views on that. How long have you been using it? Any other suggestions on extending my engine's life?

BustedRX

I disagree cpa7man. By running it until it doesnt start, you are basically committing yourself to a more expensive rebuild. unless of course your going the reman route, though with reputable rebuilds being very comparable in pricing, I cant see why you would. I know some would argue, but it still seems to be a hit and miss with the quality of the reman you get, luck of the draw if you will.

Personally Id rather park it knowing most of the internals will be salvagable and likely have a quality, professional rebuild done for the cost of a reman.

Again, bdogg, the best thing you can do to extend the life of this motor is boost it as little as possible. If you need proof simply look at non-turbo 2nd gens, they run forever.

Larz

Don't drive it period.

SNracing

do you have another car to drive? with a fd, a daily driver is always a good idea

cpa7man

iTrader: (2)

Anyway for what it's worth thats the advice from Steve Kan regarding my motor. Also I'm not aware of a lot of shops doing rebuilds. More than likely with that many miles the housings/rotors are worn and need to be replaced. Have you priced them lately. The reman is the way to go.

There are a ton of these motors running with low compression. One day they just won't start.

To answer the question about oil. I didn't mean to tell you to run synthetic oil, run a pre-mix in the gas such as a synthetic 2-cycle. It can't hurt at this point.

Also the dd advice was good. These cars make poor dd's.

SkywarpR

First off, you should have had the car checked out before you bought it, second you shouldn't have an FD if you're not gonna be able to afford to fix it. Because you are ALWAYS gonna have to fix it.

But since you've got it now, just take it easy. Get a boost gauge and learn to drive it without boost.

Mr rx-7 tt

iTrader: (5)

I have seen engines with similar compression run for YEARS! The engine may have been babied and you have carbon build up and the seals are sticking. Buy yourself some automatic transmission fluid and pour some in the motor and spin it once or twice. Now let the car set for about a week. Then pull out the plugs and purge out the ATF by turning over the motor. Reinstall the plugs and drive the car.
Drive the car until breaks...it may be a long time. Call me when you need a rebuild, reman or ported motor.

skunks

it will be cheaper to rebuild now rather to wait untill an apex seal goes and takes out your rotor housing and turbos!

Rehanke

Somethings messed up on this forum. My username is Sillbeer and I posted second on this thread and it's under someone else's username, Rehanke or something.
-Destin

t-von

iTrader: (8)

I agree! You could also attach a long vacuum line to one of the nipples on the UIM and submerge the other end into some water. Start the engine and rev it. The engines vacuum will slowly suck in the water. This will help clean out the carbon on the rotors and seals therfore helping you regain some compression. That may be all she needs. Also get a boost gauge.

teamstealth

t-Von i dont know about that one. Water injection does clean out the deposits in your engine...but ur method doesnt atomize the water, so i would advise not doing that. Plus, the engine will run longer with the carbon in there since its used to it. Ive seen firsthand a rx7 that ran strong, but it was babied. The first day it was put on a dyno and WOT'ed, carbon got blown out, and from that day on, it has had low compression and leaking turbos. Keep driving it the way its been driven, but no boost. Thats my $.02

-Zach

t-von

iTrader: (8)

Now before you disagree, go to the "General Rotary Tech Archive" section. Thats what Rob at Pineapple racing recommends. I however used fuel system cleaner on my 20b to clean out the carbon when it arrived a few months ago. It had no compression at all. Now, it has a **** load of compression.

zooq

the best mod you can get to make that motor last is a $1000 daily driver. trust me that was my best mod. ( better than power FC )

DonaldC

iTrader: (20)

I know the guy that quoted you the price. And, all I can say is he really knows his stuff. And, if he builds you an engine, it will definitely be done right. But, I wouldn't keep driving the car daily. And, I would stay out of the boost when you do drive it. Just my $.02.

s-thetikz

iTrader: (1)

your engine had only 60k miles on it and it died on you ? what the hell is that ??

btw.. how much would it cost to actually take a mechanic with you to see the car and check that its in working condition ? and is it crucial to do so ? or can you check it yourself ? thanks