VQ37VHR Motor bogging down at cold start; oil related?

[yashi]

VQ37VHR Motor bogging down at cold start in cold weather with Redline? 0w40 vs 5w40?

Coming up on my next oil change after owning my G37 for almost 50,000 miles (bought used), and I'm debating switching oil. I've been using Redline 5w30 the past 9,000 miles doing OC every 3,000 miles and I feel like Redline has made my motor very sluggish. It has that happy top end, and it certainly likes when it's warm but wow is it a dog on the commute to work. I have a full exhaust and tune fwiw..

I've read some people have been using 0w40 Mobil 1, and 5w40 Shell with these motors, worth a try? From what I understand Redline is in a higher group than Mobil and Shell so it "should be better"? I feel like Redline is too thick for my motor, maybe I'm going crazy but whenever it was around 25F or below my motor would bog down for a couple seconds then come to life. This never happened to me in the previous winters before using Redline. You can even see in my video the exhaust looks like my motor is eating some oil when it does this?

Surely there's a better oil I should be using that can safely handle 240F oil temps, but also not bog my motor when it's cold out.. I really hope someone can provide some sort of answer, this has been in the back of my head ever since I started hearing this. It's obviously gone away since it's warmed up.

 

[Glenda W.]

I’ve never seen an oil cause that.

Possibly a tune problem? To rich?

 

[SC Maintenance]

I doubt its the oil. I ran Mobil1 5W-40 Euro in my VQ40DE all last winter. We had quite a few mornings around 25F or below and started as usual.

Yours does seem to be idling quite low on cold start I will agree. I don't know how the oil would do this. I wonder if your intake air temperature sensor which is part of the MAF sensor is dirty or something?

 

[yashi]

I’ve never seen an oil cause that.

Possibly a tune problem?

That's why I'm confused because it's been tuned for years now and I haven't had this issue before!

 

[yashi]

I doubt its the oil. I ran Mobil1 5W-40 Euro in my VQ40DE all last winter. We had quite a few mornings around 25F or below and started as usual.

Yours does seem to be idling quite low on cold start I will agree. I don't know how the oil would do this. I wonder if your intake air temperature sensor which is part of the MAF sensor is dirty or something?

Fair enough, I thought maybe fuel, air or oil was too thick and it needed to build up oil pressure but that was a long shot. Everything has stayed the same and ran fine otherwise. I'm definitely interested in switching though. I'm probably wrong but I thought Redline had less cleaning properties than the usual shelf oil at the parts stores.

 

[f355spider]

Have you ever scanned for codes? Many tunes turn off the CE light, yet the codes are there to be read. Could be an O2 sensor or temp sensor, but the code is being masked by your tune.

 

[Hall]

This sounds like a weak starter to me. It really hesitates before it really starts.

Yours does seem to be idling quite low on cold start I will agree.

Yeah, doesn't seem like a "cold" start to me. My VQ35HR cold idles at around 1200 even when it's 80º+ like it is now. OP's idle sounds like it's not much higher than 650-ish which is warmed-up idle.

I run 5W-30 (usually Magnatec or GTX) mostly but have used 5W-40 (QS) and 0W-40 (Edge). As far as start-up, I've never noticed any difference across oils.

 

[yashi]

Have you ever scanned for codes? Many tunes turn off the CE light, yet the codes are there to be read. Could be an O2 sensor or temp sensor.

Fortunately Ecutek does not allow you to mess with any CELs. I have an Ecutek Bluetooth dongle that connects to their app and I have no lights or errors whatsoever. I have two brand new o2 sensors because one was loose and the wire hit the ground. One new o2 sensor fuse and two oem sensors and my car's been running great! It's just that cold start issue!

 

[f355spider]

This sounds like a weak starter to me. It really hesitates before it really starts.


Yeah, doesn't seem like a "cold" start to me. My VQ35HR cold idles at around 1200 even when it's 80º+ like it is now. OP's idle sounds like it's not much higher than 650-ish which is warmed-up idle.

I run 5W-30 (usually Magnatec or GTX) mostly but have used 5W-40 (QS) and 0W-40 (Edge). As far as start-up, I've never noticed any difference across oils.

Weak battery perhaps?

 

[JavierH19]

You sure it's not a starter or battery. No way 5w-30 is doing that at those temps. I remember my sierra struggling in the cold snap while the Yukon didn't but the battery on the sierra went out a month later. You could check the battery by putting it on a charger or maintainer overnight and if it's got a higher amp setting have it on that. If it starts normally it likely is the battery. Maybe the alternator is kicking into the high charge mode right after starting.

 

[yashi]

This sounds like a weak starter to me. It really hesitates before it really starts.


Yeah, doesn't seem like a "cold" start to me. My VQ35HR cold idles at around 1200 even when it's 80º+ like it is now. OP's idle sounds like it's not much higher than 650-ish which is warmed-up idle.

I run 5W-30 (usually Magnatec or GTX) mostly but have used 5W-40 (QS) and 0W-40 (Edge). As far as start-up, I've never noticed any difference across oils.

That's just the cold, it usually sounds like that when it's below freezing. When warm it sounds pretty healthy in my opinion, see for yourself!

 

[yashi]

You sure it's not a starter or battery. No way 5w-30 is doing that at those temps. I remember my sierra struggling in the cold snap while the Yukon didn't but the battery on the sierra went out a month later.

Battery was replaced due to the shop who sold the car giving me a cheap battery. Alternator is healthy too. Only around 120k miles in these videos.

 

[f355spider]

Battery was replaced due to the shop who sold the car giving me a cheap battery. Alternator is healthy too. Only around 120k miles in these videos.

Get a tester and test them both, that is the only way to know for certain. Then you can eliminate them.

 

[Hall]

When warm it sounds pretty healthy in my opinion, see for yourself!

That still sounds a little slow compared to mine, to be honest.

 

[ka9mnx]

I’ve never seen an oil cause that.

Possibly a tune problem? To rich?

Agree...

 

[yashi]

Agree...

Well it only started happening when I switched to Redline 5w30 so you can see why it makes no sense. I've been tuned for years and never experienced this.

 

[Jetronic]

Well it only started happening when I switched to Redline 5w30 so you can see why it makes no sense. I've been tuned for years and never experienced this.

wgich means every sensor is also years older now. Including the MAF that would be used pretty much exclusively just after startup.

 

[ka9mnx]

Well it only started happening when I switched to Redline 5w30 so you can see why it makes no sense. I've been tuned for years and never experienced this.

Well it's not an oil issue. The only way that could happen is if the crank case was overfilled.

This is a mechanical or electrical issue that coincided with the oil change.

 

[Hall]

Well it only started happening when I switched to Redline 5w30 so you can see why it makes no sense. I've been tuned for years and never experienced this.

You've convinced yourself it's the oil. Just change it to something else then.