Suspected head gasket failure - 1.5 hybrid

[Mill.69]

Hi guys

Had the hybrid a couple of months now and all has been ok ish 

The car was freshly serviced not long before I bought it by Toyota and it does have full Toyota service history

I've noticed I'm not getting great MPG which got me curious, after checking the oil level I noticed the top of the oil cap has started to go a thick dark brown colour. 

This normally indicates coolant leaking into the oil and possibly fuel which would explain the MPG.

Anyone else had a similar issue and any luck going through the 10yr warranty Toyota offer with servicing?

[anchorman]

2 hours ago, Mill.69 said:

Hi guys

Had the hybrid a couple of months now and all has been ok ish 

The car was freshly serviced not long before I bought it by Toyota and it does have full Toyota service history (2014 car)

I've noticed I'm not getting great MPG which got me curious, after checking the oil level I noticed the top of the oil cap has started to go a thick dark brown colour. 

This normally indicates coolant leaking into the oil and possibly fuel which would explain the MPG.

Anyone else had a similar issue and any luck going through the 10yr warranty Toyota offer with servicing?

No, not necessarily.  You often get emulsified oil inside the filler cap because it’s cold.  None of us are getting brilliant fuel consumption this time of year.  Monitor it for a while.  Toyota won’t jump right into surgery without some extended testing.  

[Gray86]

Try a good motorway journey in the car to get it al up to temp. It’s highly likely just emulsified oil from cold weather & short trips.

 

[TonyHSD]

Almost certain not a head gasket problem. As been mentioned if the car is used mostly on short trips and because of the cold weather it is normal occurrence to find even a mayonnaise like solution on your engine oil filer cap and in some cases on the dipstick above max oil level.
If the oil and coolant themselves are in good visual condition, no huge lost of either on them of them and no cross contamination there is no reason to worry about head gasket. Fuel consumption it’s not related to head gasket issues. You can try E5 99 petrol especially when cold it makes the engine smoother, more powered and returns better mpg 3-5 more. 👍

[flash22]

It's rare for a head gasket unless it's been thrashed or in 200k+ miles

Any drop in the coolant level ? Any emulsion on the dip stick

what do you class as low MPG ?

[Cyker]

It's almost certainly condensation getting into the oil because the engine hasn't been getting run long and hot enough - It's a very common thing in the colder months on cars that aren't driven much, not just on hybrids but straight ICE cars too - I vaguely recall a few Aygo owners posting about similar things on this forum years ago too! Hybrids do tend to be more prone to it as the engine has a much lower duty cycle (i.e. it don't run as much) than straight ICE cars tho'.

It's nothing to get too concerned about as it'll fix itself as the weather warms up and the engine gets to temp faster, but a quick way to fix it would be to go explore some of the wonderful countryside roads you have up there on the weekend!  

 

[Max_Headroom]

10 hours ago, Mill.69 said:

I noticed the top of the oil cap has started to go a thick dark brown colour. 

You say brown does it look like this?

 

[TonyHSD]

1 minute ago, Max_Headroom said:

You say brown does it look like this?

 

Is that from your car? 
that the mayonnaise I am talking about 🙂 as Cyker says it happens to all petrol cars that haven’t seen enough long use. 👍

[Max_Headroom]

7 minutes ago, TonyHSD said:

Is that from your car? 

No but i did  used to get a lot in the Corsa when i first bought it, this was not brown more a more a yellow colour hence my question, i suspected short journeys as being the cause as there was no evidence of coolant loss  a wipe with a cloth and a few trips on the local  dual carriageway soon sorted it.

[Mill.69]

Hi Guys

Thanks for the many responses, it's certainly put my mind at rest a bit, It will be going on a long run in a couple of weeks to Scotland so I'll make a note of the coolant level and see if it drops any.

Also just to answer to the picture above, no nothing like that but just a film of brown gunge. I've read that can be a certain coolant mixing with the oil to make it go that colour instead of the usual Mayo.

In terms of MPG I'm talking late 30's when bobbing around town etc but I could put it down to all the hills we have, I suppose I'm just a bit surprised as I came from the Yaris 1.4 diesel which was tremendous on fuel even bobbing around locally and expected the hybrid to be the same or better.

I'll keep an eye on it after the long trip and update here on the findings

Thanks for all the help  

[Cyker]

That sounds plausible - The 1.4 diesels tended to do better than the Mk3 hybrids on hills and faster roads, as they had a lot more torque at their disposal, esp. with the variable geometry turbo charger winding in plenty of boost even at low RPM.

I found mine really didn't like pottering about all the time and I'd have to take it on a good long hoon now and then to get it good and hot to burn off all the crud building up, or use a tank or two of V-Power diesel.

There aren't many engines that can beat the 1.4 D4D for real world mpg, even now! Not bad for a 20 year old engine!!

The Mk4 does better as it has a more powerful electric motor and the petrol engine can switch between Atkinson/Miller and Otto-cycle modes, which also means it doesn't have to rev as high to deliver torque and power under load.

[flash22]

tbh mid 30's is low, you really have to adjust your driving style with a hybrid, if it's your first auto it's one foot driving left foot does nothing, get up to speed back off the throttle and just use the top 1/4 of the pedal

A tank of decent premium fuel and some injector cleaner would be an idea

how long does the car run on the electric motor ?

 

Does the oil smell of petrol at all ? Has the oil level risen

[Cyker]

To be fair, if the journeys are short and there are lots of hills, esp. steep ones, I can see it only managing the 30s. I remember there being quite a big disparity for mpg of Mk3 owners between the city-dwelling ones and the ones living in hilly places back in the day!

If it's anything like the Mk4 it will benefit greatly from some longer journeys. While I had the windscreen crack, I switched to using the shortest routes and that plus the cold weather absolutely wrecked my mpg. As soon as I went back to the longer routes it shot back up, and as the weather's been improving that's helped nudge it back up more too!  

[TonyHSD]

Here with fuel consumption we need to be sure that has been measured correctly full to full tank and not taken information from the car dashboard as this is not very accurate and particularly on cars that have been driven on short trips mostly.
Average of 30mpg in worse conditions are acceptable for Yaris hybrid. 👍

[Cyker]

Yeah, my one is roughly 5-10% optimistic vs my calculated figures. And I wouldn't say 30mpg is acceptable, just.... expected or at least par. I must admit I'd not be super happy if my Mk4 only returned 30mpg - May as well have stayed with the petrol one!  

But my colleague only got 35-38mpg in his Auris due to short journeys and having to go over Muswell Hill every morning. He was a bit annoyed about that compared to his diesel Audi A3 (Also KHAAAAN'd) until he took it on holiday and got over 60!  

Now he goes around the hill; Takes a bit longer but the mpg is improved and tank lasts a bit longer.  

 

[Phil T]

My Prius PHV absolutely loved hills running on petrol, living near the Peak District, a bit difficult to go round 🤣

[TonyHSD]

But the hills are up and on the way back down. Basically if you go through the hill both ways first you have spent fuel but then no fuel even Battery will be full and will add extra ev time.I used to go through this area regularly before and really enjoy it. Here how looks the oil cap on a car that travel a bit every day 👌

[Mill.69]

Hi guys

Just done a calculation from the last time it had a long run, as in filled up then driven till empty without stopping and I'm getting 38.7 MPG (Whaley bridge to Dundee so pretty much all motorway)

It'll be doing that again next and I have made a mark on the coolant level to see if it moves (currently sat just below full, hmm)

I do struggle to keep the electric motor running while at home due to the hills (they're %$(ing everywhere) but like you say what goes up must come down.

I totally get the driving style thing and think I'm still getting used to it, I tend to go with get it up to speed as fast as I can then back off and maintain to keep it out of power mode.

[YarisHybrid2016]

You have a hybrid? Keep it out the power band if you want any semblance of fuel economy. 😂

You can accelerate pretty hard up to 20 MPH, then between 20-30 MPH lift off to keep it in the middle to 2/3 of the ECO band to avoid unecessarily causing the ICE to rev up (gen. 3). Very hard accel, or any power band > 20 MPH also causes the ICE to run more than about idle.

Only driving extremely hard with the heater on returns around 40-45 MPG. In minus 5 conditions I got 35 MPG, but most of that was sat idling to demist and warm the car (mostly demist).

The heater has greatest effect on MPG. In cold weather it drops MPG significantly. AC has little effect.

[TonyHSD]

Yeah, when accelerating doesn’t have to be into the power section of the power meter unless an urgent need. Keep moderate acceleration, from standstill starts delay initial transition from ev to ice, eco mode helps exactly that and once you have reached desired speed just maintain it and the car will switch between ev and ice. Trying to accelerate hard or slow will not help efficiency, also trying to keep the car in ev most of the time it’s not helpful either. Smooth acceleration and reduced use of the brakes, anticipating road ahead are the important bits. Heater does take some mpg in winter and AC does in summer, but at the end passenger safety and comfort it’s most important so few mpg up or down doesn’t really matter. Also in very cold or very hot weather the car will not go into ev mode if the Battery is outside the ideal temperature (15-25)C°, this to happen you need to set your hvac at around 20C° all year around. , with A C ON in summer and as per personal preference during winter. 

[Cyker]

I find you can dip into the first bar of the Pwr band briefly without affecting it too much, but if you want to get the high mpgs, trying to keep it in the Eco/Eco+ yields the best results.

Can be a struggle tho', as some hills, just keeping it at the top of Eco+ is barely enough to keep the car going up it!  

Otherwise all the usual eco driving tips apply; Anticipation is the biggest one, as the longer you can keep the car rolling and minimize accelerating and braking, the better the mpg, but that applies to almost all cars.

I'm not sure about the previous models, but the newer ones have this slightly asinine 'Eco score' which rates you acceleration coasting and braking out of 5 (Like I needed more judgement in my life!   ). I consistently get 1-2 for accelerating and braking (Because Acceleration is fun!  ), but 5 for coasting and still manage to keep my Mk4's mpgs in the 70's (Well, indicated; Calculated is more like 65!  ), because I'm anticipating traffic lights, other cars etc. so when they stop I've already backed off and just coast right up to them just as they move off again, saving me from wasting energy braking and accelerating again.

[TonyHSD]

Been driving with winter shoes for the last couple of weeks and yesterday switched back to my normal shoes with thin soles and it feels like I switched from normal to eco mode, I have to push a lot more to make the car going 😂

[Bernard Foy]

37 minutes ago, TonyHSD said:

Been driving with winter shoes for the last couple of weeks and yesterday switched back to my normal shoes with thin soles and it feels like I switched from normal to eco mode, I have to push a lot more to make the car going 😂

A pair of lead insoles are called for??🤣😂🤔

[Jimota]

You can’t beat a sensible pair of shoes.  Stopped wearing my platforms last year!

[Bernard Foy]

3 minutes ago, Jimota said:

You can’t beat a sensible pair of shoes.  Stopped wearing my platforms last year!

Don’t throw them away James, they will eventually come back into fashion again it may 20 or 30years, but good things come to those who wait 🤪🤔