Engine overheated and now wont start
 

About two weeks ago the low coolant light came on. When I went to check my coolant level I found some coolant had sprayed out of the reservoir onto the engine and underside of the hood. I thought that possible the cap had gone bad so last weekend I went and purchased a new cap. When I went to place the new cap on the reservoir one of the threads on the tank broke off. It broke off effortlessly so most likely it was already weakened and was the reason for the initial issue.

I ordered a new tank but while I was waiting I was driving without a cap to and from work (about 15-20 min highway). I was adding water to the reservoir an closely watching the temperature gauge. This was a very very bad idea and I think ultimately killed my engine yesterday.

Yesterday while I was driving to work the gauge suddenly rose to max. I cranked the heater to max and pulled off the freeway and into a gas station (took less than 1min). I let the engine cool some and then added water to the reservoir and then let it cool some more. I then started it up and it ran fine all the way to work.

Then on my way home the same thing happened. I pulled to the side of the road and did the same as before. At this point I was about 5mi from my house so I decided to try to make it.

About 1/4mi from my house I had the same issue happen again. I noticed this time that when I turned on the heater no heat came out, just air about the same temp as outside. I pulled into a gas station to get more water, added the water, let the engine cool and then went to start it.

At first the engine wouldn't crank at all but after a few attempts it would crank but not start. I ended up having the car toed home and am now trying to figure out what to do with it.

I have already accepted the fact that the engine is probably toast but is there any way to definitively check if that is the case? If so, could it be repaired or must it be replaced and about how much would it cost?

Any help or suggestion would be appreciated. Also if I need to take it to a shop to have it diagnosed or repaired (if possible), recommendations are welcome. I live in Newport Beach, CA. I previously had the clutch worked on at Neptune Speed (found as a recommendation on this site while lurking). I was very pleased but they typically have a very long waiting list which is ok for non-critical repairs (like my clutch) but a non-functional engine is a much higher priority.

Edit:
Forgot to mention it is an '05 RX-8 manual-6

This has got to be a troll...

Sadly it is not. All in all I'm pretty depressed and pissed at my self for doing something so stupid. Driving without the cap was not my idea by the way. I mentioned my problem to my coworker when the thread first broke and he claimed that I should be able to do what people with old leaky cars do (which was what I did as descried above). Lesson very painfully learned: Don't listen to other people just because they are older and might have marginally more experience with cars than I do.

Yes, your engine is toast. A single overheating that doesn't even move the needle can easily be fatal to our engines. The heat allows the housings to warp to one degree or another, and seals lose their ability to seal completely. The higher the overheating, the more warping there is, and the faster the compression loss. Also usually means oil control ring failure and/or coolant seal failure, letting one or both into the housings and then dumping into the exhaust. You generally can't even rebuild engines that have been overheated. The rotors and MAYBE the e-shaft are really the only salvageable parts.

You can get a compression test at a Mazda dealer to confirm the failure, but no warranty or insurance will cover this.

Your options are basically:
New engine for $3,500 to $5,000
or
sell the car for less than ~$4,000.

That's what I thought but was hoping otherwise. Since my last post I was able to get a hold of the shop I mentioned and they are going to do a diagnostics on it on Monday. I'm expecting them to say the same thing but at least I will know for sure.

you need to stop talking to him

oh before you stop talking to him, please tell him that he is a fucking moron, I don't care how old he is, if he doesn't know what the fuck he is talking about, it's better to keep his mouth shut. Just because he is old(er) doesn't mean shit. Anybody can be a moron.

ok, after you tell him what I said, you can just ignore him forever.

the coolant system needs to be pressurized to do it's job, and the cap is there just "in case" the pressure is higher than certain point which might damage other stuff (1.1).

even if the engine overheats, there is no way your electronics don't work. Unless the heat actually killed the Emission harness on top of it. but if ur car can turn on now (just not starting) then I guess it's fine for now.

if your engine is dead from overheating, I am dare to say over 90% of the components inside will NOT be re-usable. you can get a Reman from Mazda for around 2-3K, buy a manifold gasket kit for another 100-300?(I can't remember now). assume u have hand tools and a cherry picker, the swap (if doing just 1 person) probably takes 1-2 days.

if u are around NYC, I can probably do the swap for u for cheap, I want to try to swap an RX-8 Engine anyway. I have all tools and ready to work :)

please. my engine overheated on a dyno during a run to 9500 or so rpm. cloud rolling out of the hood panic ensuing etc etc etc. engine is still healthy to this day.

first get the problem of the cap etc fixed. then get your car started using the deflood procedures . make sure to burp the cooling system. then get a compression check.

pull the dipstick. smell it. does it smell like coolant? if no then do the above. if yes then get a reman etc

Key word in my post is "can".

Just like heating an iron bar till it's glowing doesn't automatically mean it will bend, it makes it quite a bit more possible. I'd say that your engine overheated and ran no more than a few seconds longer.

He overheated repeatedly with essentially no safety margin...

I smelled the dip stick and it does not smell like coolant. It sort of smells like a mechanic shop or something. In case it helps, I wiped some of the fluid onto a paper towel and posted the picture below:

Attachment 289307

How old is the oil? (time and miles)

The oil was last changed on 3/23/12 at 59161 mi. The car is now at 61688mi.

Non expert opinion is that your oil is too light colored for 2,500 miles on it. It turns black really quickly. Possible contamination?

I forgot to mention I did top off my oil a few times since that change, the last being 1qt at 61528 mi.

LOL...the infamous Wenatchee Dyno Debacle :) Thought you were going to crap your pants :)

I'm saying it looks light too.

PM sent


Give me a call.

the oil looks to light to me too

it looks fine to me.

every time u wipe it on a piece of bounty will look like that.

looks darker when u drain it.

LOL
This is fun! I wanna play.

I don't know if it is something about the absorption properties of a paper towel but ... yeah

Looks fine to me.

I'm running Royal Purple right now ... or I would go get more pics.
Maybe I will anyway.

Ok, I took a new picture of the oil. This time on the underside of a jar lid and with a reference drop of fresh oil. Left drop is from the engine the right drop is from the oil bottle.

Attachment 289306

Wow that's crazy different eh

ignore riwwp,razz and zoom, they are noobs and don't know what they are talking about :lol:

seriously, those oil looks fine, don't need to worry.

ur engine probably flooded badly, take the spark plug out, disconnect the e shaft plug and crank, see if any coolant come out of the spark plug hole

oil looks fine to me :)

earlier i meant that it looked like maybe he was using 5/20 and he should maybe have a 5/30 or heavier in there. you know because of the wicking/absorption pattern on the paper towel. yeah. thats what i meant. seriously.:uhh::squint:

I checked the viscosity of the oil and it is a little bit lighter than normal.

It's hard to tell we will drain a little to make sure but not until we get it started and the overflow replaced.

I have been using 5/20 but Razz was explaining that that is more for emissions than anything else and that I might want to move to 5/30 or even 10/30 since it is now summer and we live in a rather warm area.

Tomorrow I should be getting the new coolant tank and will be putting that in. Also going to try deflooding the engine tomorrow if all goes well.

By the end of tomorrow I should have more data for everyone to crunch on.

The deflood can be a bitch sometimes.
Stick with it.

Plugs out
ESS disconnected
Fuel Fuse pulled

5-10 seconds of cranking until you don't see anymore mist/vapour coming out of spark plug holes.

Its handy to wipe them down between cranks to see if more fuel is coming out.
And well in your case perhaps coolant.

Spare battery and/or battery charger will be necessary.

Good luck and keep us posted