Running hot after Pettit street ported engine instal
 

Hey. So I'm new here. Been browsing the forum for a few years now but haven't posted anything but desperate times call for desperate measures. So this is my third rx8 now and I've recently installed a Pettit racing street ported 13b. The engines done around 1500km so basically brand new. I recently installed gauges for water temp, oil temp and oil pressure and the readings are freaking me out so I messaged Pettit but haven't got a reply from them so far. Basically here is what's happening:

- the water temp gauge doesn't go lower than 98 degrees centigrade when the stock gauge shows normal operating temperature. Then the car gets hotter up to 105 degrees even when at idle. Fan kicks on but doesn't go below 102. It's only when I give it an extended run does the temp go down to 95. Should it be running this hot?
- I can smell coolant when my windows are down
- the gauges have been matched to obd2 readings so they're operating fine
- that's the heating issue.
- the other thing is that I'm using royal purple hps in the new engine and after 400km I got the low oil level light. I've never had the 8 go through oil like that.
- should I do an ecu remap? If so who do you think I can send it too as I live in Pakistan and I'd have to take out the ecu and send it.

It would really help if someone could help me out but I haven't been able to find out anything regarding this and what to check for when facing such issues with a new engine.

Centrigrade? We are in Murica man.

So in 1500kms break in you went thru enough oil for the low oil light to come on? I assume you have not been racing (higher load = faster consumption) it right? If it's not leaking obviously then you need to get that checked.

How did the old engine fail?

Did you flush the oil lines and oil coolers (if previous engine had bearing failure then the cooler could get clogged)?

Did you change any of the coolant hoses?

If so, did you put the copper restrictors back in the coolant lines?

Did you install a new water pump and thermostat?

So I already asked Pettit to break in the engine before shipping it to me. Installed and drove it. Was running regular royal purple initially but did an oil change at 1000km and changed it to Royal purple hps. 400km later the low oil light comes on.

My engine didn't fail I bought an rx8 with 40,000km on it with a working engine and just ordered a Pettit engine as I wanted it to run hassle free.
Did not flush the oil coolers. Oil temp barely ever touches 100 degrees centigrade so I think those are running okay. Coolant I'm worried about.
Did not change the coolant hoses and no idea what copper restrictors you're talking about.
Did not install a new water pump and thermostat either

Well, if it ran fine when they pulled the engine and you didn't replace anything then it's probably not the missing restrictors in the coolant and heater hoses (when these are missing they can cause overheating).

So, assuming they reinstalled everything correctly, then it is time for a coolant system pressure test. You also need to test the cap.

You definitely want a tune after porting the engine.

Is it possible something was broken during installation of the engine? You said you smell coolant, which means it's outside of the engine. There are common failure points in the coolant system, especially when major work in the engine bay is done: the coolant overflow bottle and the radiator neck that leads to it. Check that those aren't leaking. If they are, the coolant system can't pressurize and becomes ineffective.

Is your undertray in place?

How low was the oil level when the light went off? There is a known issue with early RX8s where the oil light will come on incorrectly.

Finally, are you sure Pettit actually broke in your engine? I don't how they would do that without installing it in a car and driving 1000km in it... did they confirm they did this for you?

Yeah there is a TSB on excessive oil consumption too relating to the OMP system, but I would address the cooling issues and go from there.

I have heard a few bad things about Pettit recently from customers so it would not surprise me if they screwed up or didn't drive it at all.

Based solely on my experience with my car:

95 C on a hot day while at cruising speed is not outside the range of normal for an RX-8, with stock cooling system. 105 degrees at idle is also possible if the outside temperature is hot enough. What is the ambient temperature when you make these observations? Generally, the fans should be capable of bringing the temperature down to 95 degrees when idling without air-con. But if you are in stop and go traffic with the air-con on, on a hot day, the temperatures you describe are within the range of what I would expect.

The stock gauge will not move until you hit 110, at which point you should urgently take steps to lower the temperature. Above 107 you are in the danger zone, and I would take steps like turning off the air-con, or slowing down, to bring it under control. It seems you have a bigger problem at idle than during cruise, so it would be wise to verify that both of your fans are operating and at the right speed.

If the coolant smell is not just in your head, is the coolant level dropping? Is your coolant bottle cap sealing properly?

Where and how does one get a tune?

The dip stick was on the last line when the oil level was low

Any leaks anywhere would show wouldn't they? Be it oil or coolant.

Nothing seems to be leaking or over flowing

Sorry forgot to mention that ambient temps are between 23-27 degrees centigrade. It's going to get hotter sooner 30+ so am in need of finding a solution to this asap so that I can avoid any possible damage

221F for any decent length of time is not okay under any normal driving conditions in those type of ambient temps. Stock RX-8's here in South Texas (130 plus days of 100F weather) that have a properly working coolant system rarely get over 210F even when beating on them on a 100F day.

That said, this may not be engine related at all since old parts of the cooling system were re used. But if they were working fine before, then they should be ok. But a lot of things can happen when removing and reinstalling an engine.

But installing a fresh rebuild without installing a new water pump and Tstat makes no sense to me. Especially if the engine had the old style water pump.

Ok, at those ambient temps your car is definitely running hotter than normal. Do what 9k and Loki say :bowdown: At cruise you should be seeing 83-90 deg coolant temps.

I mean hell, the coolant system may have just not been bled correctly. I hate shops, they all suck IMO.

Coolant dries up very quickly when when it's close to 100c in the engine bay. Try to localize it by smell. If the smell is coming from the exhaust though, that would be much worse.

A new engine would use more oil until the oil rings bed in...another reason I question that your engine was actually broken in before you got it. I wouldn't recommend using a synthetic oil for breakin, it's too slippery and things don't bed in properly. That's based on experience with piston engines, learned this once the hard way.

On the cooling side.

Check this https://www.rx8club.com/series-i-tro...o-i-do-258334/ Test the fans. Make sure they are working how they should be. They really do not come on until fairly high temps.

Then look at this https://www.rx8club.com/new-member-f...ot-8-a-202548/

Look at the air flow, foam around the radiator mods. Also Fans on low, if the fans passed the test above. Someone asked about the under tray, it needs to be there.

He should test the fans after he does other things sand still thinks there is a problem but he mentioned that they were coming on normally. And there are plenty of guys running around here without under trays who have never had cooling problems. Hell Shadycrew31 was boosted and on a stock cooling system and ran around that way year round and never had cooling issues. It should be there, but the absence of it will not cause overheating.

But really he needs to pressure test the system. If he is smelling coolant it is coming from somewhere.

Okay so what I'm still getting are a bunch of maybes....yes it's hard to diagnose this but I don't want to run the car if it's going to damage it. Here are my follow up questions:

- how can I do a pressure test of the cooling system
- a hose was cut to put an adapted for the water temp and I saw that it had some coolant around the area but solidified (the coolant is red so easy to spot)
- if I change all the hoses will that mean that they come new with the restrictors mentioned previously
- added info: I have an 06 uk spec 8 which has two oil coolers
- coolant level is barely dropping in the bottle
- it's used for a lot of inter city driving so very stop and go
- I auto x but haven't on this car yet due to the heating issue
- I know the fan turns on at 101 degrees

First things first bro, next time you're posting, convert the temps to Fahrenheit and the distance to miles. It's a lot easier for us because everyone here uses Fahrenheit and miles. They would understand you more.

Onto your issue.

These cars do smell like coolant. Specially near the radiator/coolant reservoir area. If it's obnoxiously bad, then you probably have a leak. But if it's a mild coolant smell every time you get close to the reservoir, I wouldn't worry about it.

Regarding the cooling issue, try doing the following :)

1) About the leak, maybe it's leaking from where you cut the hose to put the water temp sensor? Start the car, let it warm up and check that area for leaks. But Don't burn yourself :P report back.

2) Mark the coolant level on the coolant tank. Check after a drive and see if it has dropped. If it hasn't, check again the next day after a drive. Watch it for a week to be extra sure. Don't be alarmed if the coolant level has dropped an inch after the car has cooled down. Coolant expands as the car warms up. So, if you're checking the level, check when it's cold. Every morning would be perfect.


3) Pressure testing a cooling system is easy. Take it to any ghetto radiator shop beside the road and tell them to pressure test it. Wouldn't take 5 mins. Though you'll have to let your car cool down first. Report back.

4) Idling in hot wether does make the temps hit 105C, or 220F. Sad but true. BUT, and this is a big but, at 23-26C (73-79F) ambient temps, it shouldn't be that hot. For my car to hit 220F, it has to be at least 35C (95F) outside.

Do this test. Drive over 70km/h in 6th gear for about a minute continuously. The highway would be perfect for this. Check the temps. Does it drop to around 200F? If it does, then the problem is your fans. Your fans might be spinning, they might be loud, but they might not be spinning fast enough. The stock fans are known to slow down with age. Since you said this only happens at idle, I'm ready to bet it's the fans. But do this test first to know for sure.

Regarding the oil leak, I have no clue. Other members will help you with that :)

Good luck!

Cheers ma deers Nisaja. Will get on this pronto. Just a few questions:

Will mark the level of the coolant in the morning but do you want me to check coolant level right after a drive when the car is hot or to check the subsequent morning when it's cold again?

We have some ghetto ass shops here who don't deal with rotaries so they wouldn't know anything about a pressure test. Could you send me a link on a diy or explain it.

Muchos helpful

If you're making the coolant level when the coolant is cold, then yes, check it the next morning when it's cold. I told you to check the level right after a drive, to check if you've lost a lot of coolant. If it shows right after a drive, say it has dropped 2 inches, then it's a fairly big leak. That's why I told you that.

The pressure test is not rotary specific. They do it for every car. They just remove the coolant cap and attach their own cap. That cap has a PSI gauge. They apply pressure to the system and see if it holds that pressure. If the gauge's level holds, then it's all good. You have no leak. It's pretty simple. Don't worry about it man :)

Adding to this, make sure BOTH fans are spinning. Both will spin on low, both will spin on high. If one is bad, they do not spin at all on low, but one will come on for high. Your temp is, I believe, very close to the high fan turn on point and where you would hear a fan on high. If only one is spinning, it does not do much good. It blows the air back through the other side of the radiator and you end of recycling hot air. I just dealt with this on a car.

If you are city driving, the foam around the radiator mod is a good one. Why should be explained in the mod. It is part of the congrats thread.

Also, smell of coolant in an older 8 can be the radiator weeping. Find a way to see the top tank. Is it the same color as the bottom tank, or is it slightly coolant colored. I had a one that did this. Just smelled of coolant. There were like a billion micro fractures, all very slowly seeping coolant that would evaporate before it ever hit the ground. This made the top tank coolant colored, a bit. A new radiator took care of it.

I have 2 Pettit motors in 2 cars, both came with 180 degree thermostats installed.

Be careful checking the fans. If you cannot see them, start the car cold and watch your temps. you should see them rise, then level off for a bit when thermostat opens, then climb after all the radiator water is hot. They should then stop when fans come on. You can force the fans on with the AC, temps then should go down if the fans are working correctly. I think this is outlined in the overheat thread I shared.

Did you say the coolant is red? I don't know about UK cars, but around here Mazda coolant is green and you don't usually want to switch coolant colors, nor mix them. Different chemistry. Not an emergency but you may want to flush thoroughly and replace with original mazda coolant.

OH, so this is Pettit in the UK? PRESSURE TEST THE SYSTEM.

Pardon my ignorance, but I was not aware of a revised water pump that fit Series 1 RX8's. Obviously there is the Mazmart one, but what exactly did you mean by "old style"

Thanks

the water pump was revised by Mazda, the impeller was changed. All Mazda remans come with the updated part. The Mazmart pump is useless. Well I shouldn't say useless, just not really an upgrade and the price is nuts new.

Thank you, will look into revised part number for water pump impeller for my own rebuild. No sense putting it back in with out of date parts.