Power drop

2Cent

Member
Messages
22
Hi all, I've taken the DC5 to the track and I'm having an odd problem losing power.

On my first track day in November I realized I was very low on power and diagnosed that the VTC wasn't working so replaced it and once again had the power I'm used to. I also replaced both the VTC and VTEC filters because the rubber was old rather than being dirty. I went to the track again this past Saturday and again on Thursday and after just 2-3 laps I would again suddenly lose power. At first I thought it was intake temps (66+C) so I removed the hood and monitored the temps but it happened again. Allowing the car to cool down by running a slow lap would bring the power back and give me another 2-3 fast laps before needing to cool down again. During this power loss VTEC always engaged despite not being able to accelerate. On Thursday I noticed something else, VTEC went on/off when accelerating out of corners around 6000rpm.

This got me thinking the oil could be overheating but the water temp was fine and the fan is working. Maybe the VTC solenoid is leaking? I changed the oil and filter after replacing the VTC using Castrol Magnatec 10w-40.

My only DTC code is for the secondary o2 sensor but this has never affected power before nor should it.

Anyone experienced this?
 
Last edited:

JustinEET

Active Member
Messages
77
Sounds like you are losing oil pressure.
What oil are you using?
Do you have an oil baffle?
 

James-T

Advanced Member
Messages
568
Sounds like you are losing oil pressure.
What oil are you using?
Do you have an oil baffle?
I think it's more the VTC retarding the ignition than any oil issues - he is still hitting VTEC (which is obviously oil controlled) and that's either off or on..

I remember when I fitted an RBC and Hybrid racing throttle body to one of my EP3s, you have to swap the TPS over. I hadn't placed the TPS in the right position and the car would still hit VTEC but it was really slow. Maybe the TPS is throwing a fit when it's hot?

Just a couple of ideas..
 
Last edited:

2Cent

Member
Messages
22
Sounds like you are losing oil pressure.
What oil are you using?
Do you have an oil baffle?
Castrol Magnatec 10w40 semi-synthetic, never gave me a problem before.
No baffles, stock sump but this is happening on the straight so there isn't a need for baffles then.

Yeah my first suspicion was oil pressure but I have vtec and the VTC isn't completely disengaged like it was before so there's pressure there too just not getting the advance needed. So if the vtc engages just not all the way then it's the ecu not giving me advance timing for some reason.
 

JustinEET

Active Member
Messages
77
I think it's more the VTC retarding the ignition than any oil issues - he is still hitting VTEC (which is obviously oil controlled) and that's either off or on..

I remember when I fitted an RBC and Hybrid racing throttle body to one of my EP3s, you have to swap the TPS over. I hadn't placed the TPS in the right position and the car would still hit VTEC but it was really slow. Maybe the TPS is throwing a fit when it's hot?

Just a couple of ideas..

Well I noticed he said this
" On Thursday I noticed something else, VTEC went on/off when accelerating out of corners around 6000rpm. "

I've lost three engines total due to leaks and just oil issues.
My rod bearings were basically on there way out and the car accelerated slow enough that a prius could beat me. Because they weren't getting proper oil. During multiple left turns he might have low oil levels due to a leak somewhere. And left turns sloshes the oil up into the chain case which further increases lack of oil pressure until its able to fall back down on a slow lap. Without an oil pressure gauge installed problems like these are hard to determine. That's why I installed one that I can monitor whilst I'm out on the track. It's about as necessary as a firewall or a virus scanner on a computer.

2Cent
How are you determining that VTEC is engaging if you are on OEM ecu?
Are you going by audible sound?
I think the TPS issue would be easy to tell since the engine would run lean as the ECU would not know how much fuel is required for the amount of air its receiving .


But yeah an oil pressure gauge and an OBDII device that can show TPS/AFR readings would probably help you find out your problem.
 

2Cent

Member
Messages
22
The power was fine driving home. Intermittent issues are such s****!
Well I noticed he said this
" On Thursday I noticed something else, VTEC went on/off when accelerating out of corners around 6000rpm. "

I've lost three engines total due to leaks and just oil issues.
My rod bearings were basically on there way out and the car accelerated slow enough that a prius could beat me. Because they weren't getting proper oil. During multiple left turns he might have low oil levels due to a leak somewhere. And left turns sloshes the oil up into the chain case which further increases lack of oil pressure until its able to fall back down on a slow lap. Without an oil pressure gauge installed problems like these are hard to determine. That's why I installed one that I can monitor whilst I'm out on the track. It's about as necessary as a firewall or a virus scanner on a computer.

2Cent
How are you determining that VTEC is engaging if you are on OEM ecu?
Are you going by audible sound?
I think the TPS issue would be easy to tell since the engine would run lean as the ECU would not know how much fuel is required for the amount of air its receiving .


But yeah an oil pressure gauge and an OBDII device that can show TPS/AFR readings would probably help you find out your problem.
Hey Justin, yes I can hear Vtec engage. But again if it were oil sloshing it should happen on any lap especially the fast ones and cool down laps shouldn't make a difference to it. But yes, since I'm tracking the car I'll soon install an oil pressure gauge. The car is fine on the road so I'll have to return to the track with someone on the passenger seat watching the obd readings
 

2Cent

Member
Messages
22
Well I noticed he said this
" On Thursday I noticed something else, VTEC went on/off when accelerating out of corners around 6000rpm. "

I've lost three engines total due to leaks and just oil issues.
My rod bearings were basically on there way out and the car accelerated slow enough that a prius could beat me. Because they weren't getting proper oil. During multiple left turns he might have low oil levels due to a leak somewhere. And left turns sloshes the oil up into the chain case which further increases lack of oil pressure until its able to fall back down on a slow lap. Without an oil pressure gauge installed problems like these are hard to determine. That's why I installed one that I can monitor whilst I'm out on the track. It's about as necessary as a firewall or a virus scanner on a computer.

2Cent
How are you determining that VTEC is engaging if you are on OEM ecu?
Are you going by audible sound?
I think the TPS issue would be easy to tell since the engine would run lean as the ECU would not know how much fuel is required for the amount of air its receiving .


But yeah an oil pressure gauge and an OBDII device that can show TPS/AFR readings would probably help you find out your problem.
Follow up question, where do I install the oil pressure sensor for the gauge? And does this bypass the stock one? Could you share a diagram or pictures of this installation?
 

JustinEET

Active Member
Messages
77
The power was fine driving home. Intermittent issues are such s****!

Hey Justin, yes I can hear Vtec engage. But again if it were oil sloshing it should happen on any lap especially the fast ones and cool down laps shouldn't make a difference to it. But yes, since I'm tracking the car I'll soon install an oil pressure gauge. The car is fine on the road so I'll have to return to the track with someone on the passenger seat watching the obd readings
As the oil gets hotter it breaks down more thus the oil pressure is less. When oil sloshes up into the chain case it has to have a chance to fall back down into the sump so the pump can pump it through. Turn after Turn you are putting more oil up into that case. Then on your cool down lap I assume you aren't driving as fast so there's less G forces and the oil comes back down into the pan.
Just a theory; you could try putting more oil in just a tad over the top notch of the dipstick.
What are you oil levels looking like?


I installed mine in my air vent next to my steering wheel.
IMG_20200619_204941.jpgoil1.PNG
 

2Cent

Member
Messages
22
As the oil gets hotter it breaks down more thus the oil pressure is less. When oil sloshes up into the chain case it has to have a chance to fall back down into the sump so the pump can pump it through. Turn after Turn you are putting more oil up into that case. Then on your cool down lap I assume you aren't driving as fast so there's less G forces and the oil comes back down into the pan.
Just a theory; you could try putting more oil in just a tad over the top notch of the dipstick.
What are you oil levels looking like?


I installed mine in my air vent next to my steering wheel.
View attachment 7465View attachment 7466
That location works well but I was asking about where in the engine to install the sensor.
But it doesn't seem right that the K20A would suffer from all the oil sloshing to one side, it's a type R. I'll order an oil pressure gauge and return to the track with a passenger to watch the obd readings. I'll make a cold air intake to make sure I don't see temps of 60C plus again
 

JustinEET

Active Member
Messages
77
That location works well but I was asking about where in the engine to install the sensor.
But it doesn't seem right that the K20A would suffer from all the oil sloshing to one side, it's a type R. I'll order an oil pressure gauge and return to the track with a passenger to watch the obd readings. I'll make a cold air intake to make sure I don't see temps of 60C plus again
They all do, that's why I use this baffle to prevent it from happening instead of a full pan baffle.
IMG_20200619_193401.jpg

Blocks oil from sloshing into the chain case. And has trap doors to let any oil behind it drip back down into the oil pan.
Then I installed this line into the port for oil pressure switch that has a "T" at the end of it.
IMG_20200703_182828.jpg

From that T I plugged my OEM oil pressure sensor back in AND my aftermarket oil pressure sender on the other side.
Which sends electric signal to my oil pressure gauge. I put the wire through the firewall around the area where harness comes through.
 

carl hammond

Advanced Member
Messages
3,460
OdbII readers (if a plug and play one with an app such as torque) won’t tell you oil pressure and oil temp.

I believe to get these you need an independent setup with a gauge for each.

I also don’t think just chucking things on and hitting the track to test is the best way as if it is an oil issue you’re risking your engine.

the DC5 doesn’t have a baffled sump from factory and I’d never have risked my engine on track without one and so it was the first mod I did before hitting the track.

if you’re uncertain I’d get someone like TGM, Honda HQ or Area to have a look before you risk any unnecessary damage or add any unnecessary expenditure mate.

it does sound like an oil starvation issue to me but I’ve never had any of the issueW ruined to date so hard to say, deffo get in touch with a pro company (whichever is more local to you) ideally tgm or area as tgm used to race and still Maintain many race dc5’s or area who race and maintain the civic cup cars
 

2Cent

Member
Messages
22
That's
They all do, that's why I use this baffle to prevent it from happening instead of a full pan baffle.
View attachment 7467

Blocks oil from sloshing into the chain case. And has trap doors to let any oil behind it drip back down into the oil pan.
Then I installed this line into the port for oil pressure switch that has a "T" at the end of it.
View attachment 7468

From that T I plugged my OEM oil pressure sensor back in AND my aftermarket oil pressure sender on the other side.
Which sends electric signal to my oil pressure gauge. I put the wire through the firewall around the area where harness comes through.
I'm going to start looking into this baffle and definitely the oil gauge. I happen to have met someone recently that raced with a dc5 so I'll get his advice too.

This has alerted me to the fact that I'm not using the right oil too, 10w-40 is too thin for racing and this started on a hot day so I'll switch to a 10w-60 or 15w-60 fully synthetic.

Thanks guys. I'll try to give a conclusion here when it's sorted.
 

carl hammond

Advanced Member
Messages
3,460
That's

I'm going to start looking into this baffle and definitely the oil gauge. I happen to have met someone recently that raced with a dc5 so I'll get his advice too.

This has alerted me to the fact that I'm not using the right oil too, 10w-40 is too thin for racing and this started on a hot day so I'll switch to a 10w-60 or 15w-60 fully synthetic.

Thanks guys. I'll try to give a conclusion here when it's sorted.
My car is only used as a track car and I have only ever used the below:


Millers Oils NANODRIVE CFS 5w-40 NT+ Full Synthetic Engine Oil 2017 version and now I’m using Petronas Syntium 3000 AV 5w-40 Full Synthetic Engine Oil.

Your oil is fine. Also are you doing trackdays or racing. Racing is completely different to trackdays and tgm used 60 when racing and recommend it (for racing), for trackdays 5w-40 Full Synthetic Engine Oil is perfectly fine.
 

2Cent

Member
Messages
22
I'm in southern Africa with temperatures typically above 30C. I think I'll stay off the track in January when we see temps of 37C! I'm not racing competitively but I'm racing the clock or chasing others and each session is 30min, that's enough time to heat up the oil. This power loss first occurred on a hot day with the engine hot and high intake temps after some fast laps. The problem went away when I allowed the car to cool down so it seems heat related. Maybe the part synthetic oil cooked...

One way to test this is to install an oil pressure gauge and see if it's dropping at any point and whether different oils make a difference to it. But of course a thicker oil could cause some power loss when not at temperature.

Right now I'm only using the car for the track coz the Ohlins are just too stiff for the road and the ride height makes it prone to bottoming out.
 

JustinEET

Active Member
Messages
77
Tbh, I would stick with 5w-40 or 10w-40(Your hottest days) if you are using OEM rods with OEM bearing clearances.
If anything I would go full synthetic so it has additives that will help resist breakdown.
Here in Texas(United States) as one of the hotter states we get up to 40+C in our deep summer months.
What are your oil levels looking like after a track day?
 

carl hammond

Advanced Member
Messages
3,460
I'm in southern Africa with temperatures typically above 30C. I think I'll stay off the track in January when we see temps of 37C! I'm not racing competitively but I'm racing the clock or chasing others and each session is 30min, that's enough time to heat up the oil. This power loss first occurred on a hot day with the engine hot and high intake temps after some fast laps. The problem went away when I allowed the car to cool down so it seems heat related. Maybe the part synthetic oil cooked...

One way to test this is to install an oil pressure gauge and see if it's dropping at any point and whether different oils make a difference to it. But of course a thicker oil could cause some power loss when not at temperature.

Right now I'm only using the car for the track coz the Ohlins are just too stiff for the road and the ride height makes it prone to bottoming out.
I’d personally be using 5w-40 still or as said above maybe 10w-40 on your hotter day. We don’t have it so hot here in the uk (I wish we did) but I like you so long sessions of 30 mins regularly and min is normally 20 unless I’m testing.

mate you not using fully synthetic ? Honda recommend 5w-40 fully synthetic engine oil.
As above (what’s the oil levels before and after each session/trackday, have you tried overfilling it slightly as you don’t have a baffles sump of drop in baffle in the sump)?
 

2Cent

Member
Messages
22
Tbh, I would stick with 5w-40 or 10w-40(Your hottest days) if you are using OEM rods with OEM bearing clearances.
If anything I would go full synthetic so it has additives that will help resist breakdown.
Here in Texas(United States) as one of the hotter states we get up to 40+C in our deep summer months.
What are your oil levels looking like after a track day?
Thanks Justin, if you're fine in Houston with 10w-40 then I'll be fine too, that place is hot in summer! But yeah I'll change to full synthetic.
My oil level is still at the right level after the track day
 
Top