Hot start issue after seafoam
 

So the other day my car flooded pretty bad so I wanted to do some maintenance on it to prevent future issues, now it hardly starts when its warm. The starter sounds like it's spinning fast it just isn't turning over for a while. Any ideas what it could be? I didn't have this issue before, I'm hoping the seafoam treatment didn't damage a seal. To get it started initially I did crank it for a while and could have possibly damaged the starter I suppose. The battery is only a few months old


So here is what I did,

Gutted the cat
Replaced the 0² sensor and added a spacer
Seafoamed the engine letting the seafoam soak over night
Replaced the plugs and wires

There are others here who will be able to supply a more detailed answer, but if you can post a video, that'd help. When you say the starter is spinning fast, but it's not turning over, do you mean you can hear the starter but the engine isn't turning over, or do you mean it just turns over but doesn't actually start? If you hear the starter but the engine isn't actually turning over, you've damaged the starter. If this only happens when the engine is warm, compression leakage is possible. But DON'T freak out yet! Seafoam is also known to foul plugs, and RX8's like to be maintained regularly, anyway. If it's been 25-30k since the plugs, wires, and coils have been replaced, you'll def need to replace them.

The starter is engaging and it is trying to start the car, the car will eventually start it just could take 20-30 seconds of cranking. I got all the seafoam out and then changed the plugs and wires still having the same issue. How could the seafoam damage the engine and all of a sudden give it low compression?

It is possible that you have loosened up some carbon and gummed things up a bit

Start it and take it out for a burn and see if it gets better........

Ok so when I go to start it when the engine is still warm it won't start until I smash down the gas, cutting out the fuel pump, for a few seconds after releasing the gas then it will eventually start. I have not replaced the coils, or replaced the starter.

Should I seafoam it again?

No.

Let me also say that I have built plenty of engines in the past and seafoamed plenty of cars but my knowledge of the rotary engine is limited. Don't know if it matters but my car has a SOHN since 52k and I only inject idemitsu. A couple questions,

Is there a separate coolant temperature sensor then what the gauge uses to take a reading? If that was bad that would cause an issue.

Is there a separate intake air temp sensor besides the one in the MAF?
I just cleaned the MAF 6 months ago.

Could the seafoam have evaporated causing the carbon to reharden on a different surface since I left it over night? If that's the case then I would need to seafoam again.

Are there any sensors/connections on the airbox that could have been damaged during removal and reinstallation when I did the seafoam that would contribute to this issue?

While I was attempting to start it after the initial flood could I have damaged the new battery or old starter?

You could look at a pic of a rotary, and see that the apex seals contact the inside of the combustion chamber - when the apex seals wear, it causes compression loss due to "blow by" of sorts. Carbon build up could have actually been filling the gap between the seals and chambers, and removing the carbon could've widened the gap causing a drop in compression. Again, like others said it could be other things. Hard to diagnose over the net of course, but hopefully this helped explain why sea foam could've contributed. Not knocking sea foam - I use it for many things. But you should only leave it in for around 15 mins.

And also it may be a long shot but do a forum search and follow the NVRAM procedure. Could just be a quirk the ECU needs to work out via relearn.

Let's take a step or 2 back. Your car flooded, which is not a normal occurrence already. Has it been flooding a lot lately? You mention changing spark plugs and wires, but the main culprit is usually the ignition coils. You definitely need those to be changed if they're older than say 25,000mi.

Depending on how you performed the Seafoam procedure, the only mistake I can think of is hydrolocking. If you put too much liquid, you can definitely break a seal that way.

So my bet is Seafoam isn't the main cause here. What's the history of the car like? Can you get a compression test? (I mean, you're showing symptoms.. so..)

The ECU gets air temp data from the MAF, there is no separate air temp sensor. There is only one coolant temperature sensor and it is located on the Front cover.

Why did you seafoam? Research would have told first how to do it based on Mazda's recommendation (zoom zoom cleaner is the same shit) and it would have told you that it is pointless to do. That said, what's done is done and don't seafoam again.

Chances are there was already a loss in compression or during the seafoam process you caused an issue.

You can do a compression test to verify or take the plugs, rotate the engine and with a light boroscope look and see if you see any missing apex seals. But if the seals are still there I still recommend a proper rotary compression test.


Tyler, before you start offering up advice I would make sure you study the engine and try to understand where carbon build up occurs. It's not on the face of the housings...........

The more I think about it the more I think it may be a starter related issue. I only sucked up about 9oz of seafoam and that was sucking it up with the starter motor, not while the car was still running.

I am going to hook up my 300watt booster to it and start it hot that way, if it fires right away I know the problem lies in either the battery or the starter, both simple fixes.

I am also going to change the coils, any suggestions on the best coils that arent super expensive like the Black Halo coils?

You can use coils from the local auto parts store. They are OEM coils that may be of an earlier revision (A or B) or even the latest and greatest revision (C). A and B coils last around 20-30K miles on average. C coils are supposed to last a little longer, but there is no consensus on how long. If you want to be sure you are getting C coils, inspect the coils in the box before you check out or order them from MazMart.

Wasn't intending to misspeak..if i'm wrong, i'm wrong, but I was under the understanding that it builds up on the rotor, including the apex seals? Isn't that why it's necessary to rev it high regularly? Not arguing; genuinely asking as I was obviously misinformed.

Hang on, you've sucked in 9oz of liquid while the car wasnt running and let it sit? That's.. not how any of that works.

The Apex seal is constantly scraping against the housing, so think about that for second, how would carbon build up there? Carbon builds up on the rotor face and in the seal grooves, and on the apex seal springs, side seals, etc. Typically if the Apex seal springs or side seals get gunked up with carbon then they can start sticking, causing a loss of compression. Mazdas "Zoom Zoom" cleaner and process is meant to clear up some of that carbon in order to "unstick" a seal and then improve the compression results enough to where they can deny a warranty claim. That carbon that may be removed would be back in no time. 90% of carbon build up is from gasoline and burnt oil that is injected during the combustion process to cool and lubricate the seals. All you can do to help prevent it is use a SOHN adapter (to inject oil that is meant to burn ashless) and try and find really good clean gas (pretty hard to do depending on where you live).

Seafoam doesn't do jack shit to remove any of this baked on carbon and the miniscual amount that it does remove would be back on in no time. Now, if you let 9oz sit in there then you have a chance of getting a chuck or two to fall off it the engine is high mileage and if that happens then there is a theory that those chucks can cause issues but personally I don't think so. Overall seafoaming is huge waste of time (and money due to potential damage caused by doing it wrong) and the first time you tear down a Renesis you will see why.

It takes blasting or hours of scrubbing with a wire brush in solvent much stronger than seafoam to get that carbon off so there is not way in hell seafoam is doing jack shit to that carbon build up.

That will do it, :lol:

I really dont think I did any damage from the seafoam from what I read. I think I overheated and damaged the starter when I was trying to unflood and possibly the battery as well.

I am going to replace the coils, starter and get a new warranty battery, wish me luck.

We can wish you luck, but let's think about this. Your issue occurs when the engine is warm. The battery and starter should act roughly the same whether cold or hot, right?

Coils could certainly be playing into it, and should be replaced, but let's call a spade a spade: something's wrong with the engine.

Unless the thread title is wrong and the issue occurs hot or cold...?

Agreed, but how can that happen after seafoam, it's honestly impossible... I don't have aa lot of love for this car, its simply a winter car... I'll just sell it and get an old fashioned Honda/Toyota

It's not impossible if you put a cup of liquid in the engine ;)

But let's see how things progress..

So an update, I replaced the coils it still had trouble starting when its hot but it felt a lot more "peppy". Then I replaced the starter and BAM, this thing starts better then it ever did, instant start, faster then a brand new car, and that is with a bad battery!

When I was taking the old starter out it was in rough shape, main wire was all corroded, and extremely rusted, this looks like it was the original starter.

Yep, hopefully that new starter isn't masking a compression issue but only time will tell. Glad you got it sorted.

Cool, glad you got it sorted!

I was thinking it could be masking it as well but I think I burned the starter out a little when it flooded and then a little more when I did the seafoam, then finally killed it the past couple days trying to start it repeatedly waiting on a new one. The auto parts store tested it and said it was bad, and the main cable going from the solenoid to the starter was as green as my grass, and I water that every day.

i also have a hot starting issue with my 2004 series 1 i just purchased upon buying it the seller told me that the stock starter motor was rubbish so i have just purchased a 2.7kw starter and am having it installed tomorrow but it refuses to start after driving for only 10 minutes. it will fire when pushed and clutch started, im really hoping when this new starter is installed my worries will be over, other than that the car drives and goes great, just hope this is my issue i will let yous know tomorrow