Lost 50% of my power in 45C/113F weather??
10-20-2015, 08:15 AM
#1
Lost 50% of my power in 45C/113F weather??
Hi guys,
I have a 2004 RX-8 from the UK, and this summer I had the problem of extreme power loss.
It was hot outside (45C, 113F), in the city, with the sun shining, and the car just didn't have any power. I kicked it to the metal at the traffic lights and was overtaken by regular cars like a VW Up, so at that point I assume I had around 100bhp... I couldn't even get it to 7K RPM as the backfire and hesitation got so bad.
I was in the middle of my trip back home (300 miles away), and my heart sank, thinking I blew my engine, as during accelerations, I got quite some backfire.
I got out of the car and was shocked when I got out of my RX which was cooled at max AC power. Then when I openend my hood, it was like a fist of fire punched me in my face. It had to be atleast 50 degrees where I was standing at that moment, and was less surprised that it drove like ****. The car did start without any trouble tho, 1,5 seconds of cranking and it started, like always. Knowing that trouble during hot-starts suggests weak compression, given that it starts effortlessly in this hellhole meant that atleast that was alright.
I wondered if I should bring it to a service, or just wait, but decided to just atleast get out of the city, atleast to the sub-urbs. I had trouble getting the car over 100km/h, then I got it steady at 120km/h. As the temperature decreased, so did my power increase again. Until it was around 25 celsius and I was driving again with 180km/h with ease over the Autobahn...
Anything else on my dashboard was okay, as did the coolant temp, neatly in the middle as always when it warms up. I went to the dealership and they said that it might be the MAF sensor, but otherwise they wouldn't know. I asked if there was a PCM update for that, and they didn't know...
What happened? A friend of mine told me recently he had the same happening to him, and he has a VW GTI Turbo which also drives terribly in hot weather.
I have a 2004 RX-8 from the UK, and this summer I had the problem of extreme power loss.
It was hot outside (45C, 113F), in the city, with the sun shining, and the car just didn't have any power. I kicked it to the metal at the traffic lights and was overtaken by regular cars like a VW Up, so at that point I assume I had around 100bhp... I couldn't even get it to 7K RPM as the backfire and hesitation got so bad.
I was in the middle of my trip back home (300 miles away), and my heart sank, thinking I blew my engine, as during accelerations, I got quite some backfire.
I got out of the car and was shocked when I got out of my RX which was cooled at max AC power. Then when I openend my hood, it was like a fist of fire punched me in my face. It had to be atleast 50 degrees where I was standing at that moment, and was less surprised that it drove like ****. The car did start without any trouble tho, 1,5 seconds of cranking and it started, like always. Knowing that trouble during hot-starts suggests weak compression, given that it starts effortlessly in this hellhole meant that atleast that was alright.
I wondered if I should bring it to a service, or just wait, but decided to just atleast get out of the city, atleast to the sub-urbs. I had trouble getting the car over 100km/h, then I got it steady at 120km/h. As the temperature decreased, so did my power increase again. Until it was around 25 celsius and I was driving again with 180km/h with ease over the Autobahn...
Anything else on my dashboard was okay, as did the coolant temp, neatly in the middle as always when it warms up. I went to the dealership and they said that it might be the MAF sensor, but otherwise they wouldn't know. I asked if there was a PCM update for that, and they didn't know...
What happened? A friend of mine told me recently he had the same happening to him, and he has a VW GTI Turbo which also drives terribly in hot weather.
10-20-2015, 08:29 AM
#2
Water Foul
The heat is likely a symptom of another problem and not the cause of your car's poor performance.
When did you last replace the coils, wires, and plugs (they only last 20-30K miles)? When did you last change the air filter and clean the MAF sensor? Have you inspected the catalytic converter for clogs? Have you noticed your check engine light blinking?
The reason I am going down this line of thinking is the backfires. Backfires occur when hot fuel and/or oil reach the oxygen-rich environment of the tailpipe. The 2 most common reasons that fuel/oil might be there are incomplete combustion and rich mixture. Incomplete combustion can be caused by poor ignition.
If you let the ignition system go too long, the resulting fuel/oil in the exhaust will clog the cat, which will rob further power from the car and eventually push enough hot backpressure to destroy the engine.
If the ignition and cat are in good condition, then start going down the path of diagnosing rich mixture.
My car does love the cold, but it does not perform poorly in the heat. I live in North Texas, where the temperatures reach 110F+ in July and August FWIW.
When did you last replace the coils, wires, and plugs (they only last 20-30K miles)? When did you last change the air filter and clean the MAF sensor? Have you inspected the catalytic converter for clogs? Have you noticed your check engine light blinking?
The reason I am going down this line of thinking is the backfires. Backfires occur when hot fuel and/or oil reach the oxygen-rich environment of the tailpipe. The 2 most common reasons that fuel/oil might be there are incomplete combustion and rich mixture. Incomplete combustion can be caused by poor ignition.
If you let the ignition system go too long, the resulting fuel/oil in the exhaust will clog the cat, which will rob further power from the car and eventually push enough hot backpressure to destroy the engine.
If the ignition and cat are in good condition, then start going down the path of diagnosing rich mixture.
My car does love the cold, but it does not perform poorly in the heat. I live in North Texas, where the temperatures reach 110F+ in July and August FWIW.
10-20-2015, 02:18 PM
#3
This situation is almost effect all cars because hot weather is less density of air and engine make less power. Maybe your fuel quality effect it a bit more, this situations effect afr readings. Because maf reading effect directly to your engine.
Dont worry be happy bro.
Dont worry be happy bro.
10-21-2015, 08:05 AM
#4
Lost 50% of my power in 45C/113F weather??
This situation is almost effect all cars because hot weather is less density of air and engine make less power. Maybe your fuel quality effect it a bit more, this situations effect afr readings. Because maf reading effect directly to your engine.
Dont worry be happy bro.
Dont worry be happy bro.
OP, listen to Steve Dallas' advice.
10-21-2015, 04:56 PM
#5
10-22-2015, 04:03 PM
#7
The heat is likely a symptom of another problem and not the cause of your car's poor performance.
When did you last replace the coils, wires, and plugs (they only last 20-30K miles)? When did you last change the air filter and clean the MAF sensor? Have you inspected the catalytic converter for clogs? Have you noticed your check engine light blinking?
The reason I am going down this line of thinking is the backfires. Backfires occur when hot fuel and/or oil reach the oxygen-rich environment of the tailpipe. The 2 most common reasons that fuel/oil might be there are incomplete combustion and rich mixture. Incomplete combustion can be caused by poor ignition.
If you let the ignition system go too long, the resulting fuel/oil in the exhaust will clog the cat, which will rob further power from the car and eventually push enough hot backpressure to destroy the engine.
If the ignition and cat are in good condition, then start going down the path of diagnosing rich mixture.
My car does love the cold, but it does not perform poorly in the heat. I live in North Texas, where the temperatures reach 110F+ in July and August FWIW.
When did you last replace the coils, wires, and plugs (they only last 20-30K miles)? When did you last change the air filter and clean the MAF sensor? Have you inspected the catalytic converter for clogs? Have you noticed your check engine light blinking?
The reason I am going down this line of thinking is the backfires. Backfires occur when hot fuel and/or oil reach the oxygen-rich environment of the tailpipe. The 2 most common reasons that fuel/oil might be there are incomplete combustion and rich mixture. Incomplete combustion can be caused by poor ignition.
If you let the ignition system go too long, the resulting fuel/oil in the exhaust will clog the cat, which will rob further power from the car and eventually push enough hot backpressure to destroy the engine.
If the ignition and cat are in good condition, then start going down the path of diagnosing rich mixture.
My car does love the cold, but it does not perform poorly in the heat. I live in North Texas, where the temperatures reach 110F+ in July and August FWIW.
Spark plugs and cables are no problem, the thing is, how do I find the right coils? Will aftermarket do, or do I need originals from Mazda?
I also get this hesitation in high rpm, and I have read that the problem is quite widespread among brands of cars. Most of them assume the Air-Mass Meter.
But as I said, I will replace the coils/cables/plugs anyway.
10-24-2015, 05:27 PM
#9
Water Foul
Yes, RIWWP does an excellent job of explaining your coil options in that sticky.
And bogging down at higher RPM is a sign of both poor ignition and a clogged cat.
[Edit]
Here is the relevant portion from this thread, which is invaluable:
- The Cheapest option: BWD/Intermotor coils from auto parts stores like Advance Auto. These ARE OEM coils, just being sold to auto parts stores directly from the original manufacturer. This is common for virtually every OEM part for any car older than about 5 years old. 4 coils, 4 plugs, and 4 wires can be had for around $190-220 total based on whatever promotion is running at the time, shipped to your door for free. They are considered to be the first coil revision and you should expect to need to replace them around 20,000 miles, 30,000 miles max. They often come with a "lifetime warranty" by the auto parts store, which could potentially be leveraged for perpetually new coils.
- The Best Upgrade: The BHR ignition coil upgrade can be had for around $500, which eliminates the need to continue replacing coils periodically, as well as deliverying a significantly stronger spark for minor mileage and power gains. It is a proven kit with top notch customer service supporting it. It includes the wires, you still need to add plugs ($80)
- The For-Sure OEM: Mazmart sells all 4 coils of the latest OEM coil revision (C) for around $250, (just the coils, you still need to add plugs and wires) Supported by top notch customer service. They will likely last longer than 30,000 miles, but we don't have much solid data on how long the latest coil revision will last. If you are having trouble getting other coil options where you live, or are wary about purchasing coils from other sources, then this is your cheapest option for coils straight out of the Mazda dealer parts network.
- The Most Expensive option: Buying from a dealer will run you around $300+ for the coils, $500+ for coils, wires and plugs, and if you have them do the install, expect to get a bill for anywhere from $700 to $1,800. You may not get the latest coil revision, and it is unlikely that the dealer or techs will be able to tell you what coil revision you have. Yes, you are getting shafted if you take this option, so bring lube.
- The Highest Risk option: Ebay coils continue to pop up as counterfeit, mislabeled, dead on arrival, and have zero post-purchase support largely. They are the "cheapest" listed price, but when you add that $92 or whatever to the price of anything in the list above from having to do it over again, you can see that they are no longer the cheapest option. Do it right the first time. "Motor King" coils are popping up at an attractive price on Ebay, but are being proven as ineffective, to the point of being unable to get the engine fired. "Mazda" branded coils on ebay are almost always counterfeit. Check the seller's name though, since some of our vendors sell legitimate coils there. The price will be $200+ though. Anything sold as "Mazda OEM" under ~$26 per coil should really be considered as suspect and probably counterfeit.
Plugs
Always go with OEM plugs. The only reason to go with anything else is if you are turbocharged or supercharged, have researched ALL the options, and decide to go with something different. Even most FI setups use OEM plugs.
NGK brand, two each of:
RE9B-T <- (trailing / top plugs)
RE7C-L <- (leading / lower plugs)
You can get them from most vendors, Amazon, and autoparts stores easily. The price range is $18-$20 for each plug typically, $72-$80 + shipping total.
Note:
Be wary of "LSx D585 coil upgrades", as not all D585 coils are created the same, and the standard generic D585 coil is not properly designed internally for the RX-8's ignition needs. They generally "work", but there are anomalies and performance issues that have to be solved, if they can be solved. Definitely NOT a plug and play option, even if it is advertised as "plug and play". There is a lot more on the subject to understand, so it would be to your benefit if you learned about the needs prior to making a purchase.
.
And bogging down at higher RPM is a sign of both poor ignition and a clogged cat.
[Edit]
Here is the relevant portion from this thread, which is invaluable:
- The Cheapest option: BWD/Intermotor coils from auto parts stores like Advance Auto. These ARE OEM coils, just being sold to auto parts stores directly from the original manufacturer. This is common for virtually every OEM part for any car older than about 5 years old. 4 coils, 4 plugs, and 4 wires can be had for around $190-220 total based on whatever promotion is running at the time, shipped to your door for free. They are considered to be the first coil revision and you should expect to need to replace them around 20,000 miles, 30,000 miles max. They often come with a "lifetime warranty" by the auto parts store, which could potentially be leveraged for perpetually new coils.
- The Best Upgrade: The BHR ignition coil upgrade can be had for around $500, which eliminates the need to continue replacing coils periodically, as well as deliverying a significantly stronger spark for minor mileage and power gains. It is a proven kit with top notch customer service supporting it. It includes the wires, you still need to add plugs ($80)
- The For-Sure OEM: Mazmart sells all 4 coils of the latest OEM coil revision (C) for around $250, (just the coils, you still need to add plugs and wires) Supported by top notch customer service. They will likely last longer than 30,000 miles, but we don't have much solid data on how long the latest coil revision will last. If you are having trouble getting other coil options where you live, or are wary about purchasing coils from other sources, then this is your cheapest option for coils straight out of the Mazda dealer parts network.
- The Most Expensive option: Buying from a dealer will run you around $300+ for the coils, $500+ for coils, wires and plugs, and if you have them do the install, expect to get a bill for anywhere from $700 to $1,800. You may not get the latest coil revision, and it is unlikely that the dealer or techs will be able to tell you what coil revision you have. Yes, you are getting shafted if you take this option, so bring lube.
- The Highest Risk option: Ebay coils continue to pop up as counterfeit, mislabeled, dead on arrival, and have zero post-purchase support largely. They are the "cheapest" listed price, but when you add that $92 or whatever to the price of anything in the list above from having to do it over again, you can see that they are no longer the cheapest option. Do it right the first time. "Motor King" coils are popping up at an attractive price on Ebay, but are being proven as ineffective, to the point of being unable to get the engine fired. "Mazda" branded coils on ebay are almost always counterfeit. Check the seller's name though, since some of our vendors sell legitimate coils there. The price will be $200+ though. Anything sold as "Mazda OEM" under ~$26 per coil should really be considered as suspect and probably counterfeit.
Plugs
Always go with OEM plugs. The only reason to go with anything else is if you are turbocharged or supercharged, have researched ALL the options, and decide to go with something different. Even most FI setups use OEM plugs.
NGK brand, two each of:
RE9B-T <- (trailing / top plugs)
RE7C-L <- (leading / lower plugs)
You can get them from most vendors, Amazon, and autoparts stores easily. The price range is $18-$20 for each plug typically, $72-$80 + shipping total.
Note:
Be wary of "LSx D585 coil upgrades", as not all D585 coils are created the same, and the standard generic D585 coil is not properly designed internally for the RX-8's ignition needs. They generally "work", but there are anomalies and performance issues that have to be solved, if they can be solved. Definitely NOT a plug and play option, even if it is advertised as "plug and play". There is a lot more on the subject to understand, so it would be to your benefit if you learned about the needs prior to making a purchase.
.
Last edited by Steve Dallas; 10-24-2015 at 09:19 PM.
11-10-2015, 08:57 AM
#10
It happened again, and only when the sun started shining. As soon as the sun was gone, I regained full power again. I have no idea what's going on. I've driven distances of 600 miles regularly, and it only happened twice, when the sun was shining on the hood. When I opened the hood, it was alot warmer that usual. I had low performance, with misfire, and didn't get over 180km/h. In the evening when the sun set I got to 230km/h on GPS and 235 on the dash fairly easily?
But I don't want to base the cause on coincidences. It could be something completely different, and I'm looking for a place where to buy the coils/cables/plugs so I can replace them and atleast eliminate that being the problem.
But I don't want to base the cause on coincidences. It could be something completely different, and I'm looking for a place where to buy the coils/cables/plugs so I can replace them and atleast eliminate that being the problem.
11-11-2015, 01:39 PM
#12
Replace the spark plugs, ignition coil, and ignition wires. Check the catalytic converter, clean/replace air filter. Then get back to us. Do the usual routine maintenance BEFORE posting back. Chances are, keeping everything in good health will keep you out of trouble.
