HV battery Oil pan pre-heating in winter

From Chat GPT


In a gasoline hybrid car, both oil temperature and engine temperature play important roles in fuel consumption, but engine temperature is typically more critical for fuel efficiency. Here's why:

1. Engine Temperature:
   • The engine needs to reach an optimal operating temperature (usually around 190-220°F or 88-104°C) for fuel to burn efficiently. When the engine is cold, it runs less efficiently, consuming more fuel because it uses a richer air-fuel mixture to prevent engine damage.
   • A fully warmed-up engine operates more efficiently, reducing fuel consumption and emissions.
2. Oil Temperature:
   • While oil temperature is also important, it mainly affects engine lubrication and reduces internal friction. If the oil is too cold, it may not flow well, leading to increased friction and wear, which can impact fuel efficiency in the long term.
   • Oil temperature needs to be at a certain level to provide effective lubrication, but it’s generally not as critical as engine temperature for immediate fuel efficiency.

In a hybrid system, the electric motor can assist during colder engine temperatures, which can help reduce the fuel consumption penalty until the engine warms up. However, once the engine reaches its optimal operating temperature, it can deliver maximum fuel efficiency, making engine temperature the more crucial factor for day-to-day fuel consumption.

 

Thank you Mendel and Max 2.

Did the wire insulation melt near the block heater or near the plug? Melting is usually caused by undersized copper wires, copper is very expensive and they try to save on it.

Today I laid down some cardboard boxes on the floor, I removed the underbody cover and measured the depth of the hole, it' s 70mm I couldn't stick a caliper in there to measure the diameter, but I think all block heaters for jap cars use a standardized size, so 18mm, I attached a screenshot of a Mitsubishi forum .


Further I found and ordered standard heating cartridges of same size and rated 380 W 230v, they are sold in pairs, 22 euro including shipping.

https://a.aliexpress.com/_Exuv8OY


The heater is 85mm long, the first 10 mm are just contacts sinked in the ceramic insulation and protected by metal case I'll make a clip with a metal strip and a small hose clamp to fix it to the cylindrical cartridge and click it in to the right position on the engine, similarly to the genuine one, I'll apply some termal compound in between.

I also ordered a few waterproof plugs and sockets for the wiring .

Looking forward to delivery and assembly.

https://a.aliexpress.com/_EIsVRV6

 

ok, I think it wasn't the copper wire thickness the issue here, but the element heat.

If the wires were insulated with fiberglass cloth or silicon instead of standard pvc maybe the short was avoided.

I see DEFA uses a different design where a 10 cm rod between heater and wire dissipates part of the heat and keeps the wires away from each other.


I think the missing heat transfer grease is indeed responsible for making the wire's life even worse.

I'll see if I can find some extra fiberglass sleeves for mine like this

 

Still waiting for the parts to arrive, but what about engine block and oil pan insulation?
I See BMW claims their insulation speeds up warm up, slows down cool off, lowers emissions and fuel consumption.



Would it be beneficial on our engine? I found this 10 mm foam with a layer of aluminum foil,
the idea is to cover front, back of engine block and the timing chain carter.
It would be an addition to the grill block, and could be removed in summer like a diaper


https://a.aliexpress.com/_EylncS8

 

installed block heater, I went through different kind of clips, at the end I preferred to insert it all the way in and and block it with an old bike spoke.
The undervoltage circuit failed, I've ordered another one.
The oil pan heater smokes and burns, it switches on and off once too hot, so I opted to remove it.
Installead instead an oil pan thermal insulation, that I' ll remove in the summer.

 

Yes, correct, it doesn't adhere to the groves, I have tried also to apply it on the vertical aluminium wall of the carter, there you have a nice flat surface, but still there is a shallow grove.

 

The block heater doesn't smell and fits well, only I had to decrease the diameter from 18 to 17,5 mm with sand paper, here are 2 different clips, made out of a bike spoke.

The first clip is fixed to the heater body with a hose clamp, 1 cm of the heater remained out of the engine block causing the contacts and the silicon sealant to become so hot I couldn't hold my fingers on it.
Since the contacts are very close to the hybrid system wire harness I decided to go for a different solution.

The second clip allows the heater to go all the way into the engine block, this time the contacts and the red sealant are cool and I can hold my finger on it. I fixed a bike spoke to a hole with a bolt and made a 90 degrees corner to hold heater in position.

I also applied a heat sink compound on the heater.

The cost of the heat element was 22 euro for 2 pieces, but If I had to do it again I would search for a 17 mm diameter one with a lengt of 80 mm or even 70 mm so that it can be held in place with a C lock ring or a c shaped piece of spoke.

I applied high temp silicone sealant on the wires and slide an extra glass fiber hose on each pole, plus grounded the power cable to the engine block on a EGR screw