Diagnosing oil consumption

Diagnosing oil consumption

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Howard-

Original Poster:

4,950 posts

201 months

Monday 24th April 2017
quotequote all
Hi all,

My other half's 2007 Toyota Auris (1.6 VVTi) uses a bit of oil. I usually have to put in about 750ml every 1000 miles or so.

As far as I can tell there's no signs of a leak, and I've not noticed any blue smoke while driving.

What I haven't done yet is check and clean/replace the PCV valve, or check for any blue smoke when starting up from cold (apparently a symptom of worn valve stem seals).

Is there anything else I can check for?

Is it that much of a big deal if it's in otherwise fine mechanical fettle? It drives fine, revs nice and freely, idles fine, the fuel economy is fine, there's no mayo in the filler cap or anything like that. Oil is always pretty clean.


Thanks!

Heaveho

5,279 posts

173 months

Monday 24th April 2017
quotequote all
Howard- said:
Hi all,

My other half's 2007 Toyota Auris (1.6 VVTi) uses a bit of oil. I usually have to put in about 750ml every 1000 miles or so.

As far as I can tell there's no signs of a leak, and I've not noticed any blue smoke while driving.

What I haven't done yet is check and clean/replace the PCV valve, or check for any blue smoke when starting up from cold (apparently a symptom of worn valve stem seals).

Is there anything else I can check for?

Is it that much of a big deal if it's in otherwise fine mechanical fettle? It drives fine, revs nice and freely, idles fine, the fuel economy is fine, there's no mayo in the filler cap or anything like that. Oil is always pretty clean.


Thanks!
Interesting. I've been in exactly the same situation for 6 years or so with a car I own. I tried a few things including using a slightly heavier grade of oil, which did help. I've stopped worrying. It drives as well as ever.

trickywoo

11,706 posts

229 months

Monday 24th April 2017
quotequote all
A compression test would give you an indication if it's cylinder / rings related.

With no leak 4.5 litres over say a 6k mile change interval is pretty heavy consumption.

Has it done lots of miles and do you know it's history?

Howard-

Original Poster:

4,950 posts

201 months

Tuesday 25th April 2017
quotequote all
trickywoo said:
A compression test would give you an indication if it's cylinder / rings related.

With no leak 4.5 litres over say a 6k mile change interval is pretty heavy consumption.

Has it done lots of miles and do you know it's history?
Not really - 61k miles. Full Toyota service history, kept up by us.

Checked this morning on startup and there wasn't the slightest puff of anything when the engine started, and just the usual condensation steam when it drove off.

steveo3002

10,494 posts

173 months

Tuesday 25th April 2017
quotequote all
arent they well known for it , google toyota oil consumption and theres loads of info on them

Howard-

Original Poster:

4,950 posts

201 months

Tuesday 25th April 2017
quotequote all
steveo3002 said:
arent they well known for it , google toyota oil consumption and theres loads of info on them
The older engines are. The engine in the Auris is a generation newer although I suppose certain traits could carry over.

Heaveho

5,279 posts

173 months

Tuesday 25th April 2017
quotequote all
Howard- said:
The older engines are. The engine in the Auris is a generation newer although I suppose certain traits could carry over.
I've grown up and worked with Japanese cars, and my default position is that I don't expect them to use oil, although you see the occasional one. In my experience, it's German stuff that uses oil, sometimes at an alarming rate, despite the manufacturer claiming it to be acceptable. Therefore a little ironic that my Boxster uses none, but the Evo does.

Howard-

Original Poster:

4,950 posts

201 months

Monday 8th May 2017
quotequote all
OK so I've checked for blue smoke when starting from cold... Absolutely nothing. Not a puff.

I've also had someone follow me whilst I drive and put the engine under varying amounts of load / overrun, and not a single puff of blue smoke there either.

I'm confident it's not leaking it, as there's no sign apart from a little tiny bit of oil around the chain tensioner seal area.

If it's burning it (in any meaningful quantity), surely this would be evident through the exhaust pipe?

Still need to check the PCV valve but this looks like a right sod of a job since all the inlet manifold etc needs to come off... Is there another way of checking this without accessing the valve directly? I'm considering buying a vacuum gauge in order to check the engine's health.. Will this highlight PCV issues?

Howard-

Original Poster:

4,950 posts

201 months

Thursday 20th July 2017
quotequote all
Howard- said:
OK so I've checked for blue smoke when starting from cold... Absolutely nothing. Not a puff.

I've also had someone follow me whilst I drive and put the engine under varying amounts of load / overrun, and not a single puff of blue smoke there either.

I'm confident it's not leaking it, as there's no sign apart from a little tiny bit of oil around the chain tensioner seal area.

If it's burning it (in any meaningful quantity), surely this would be evident through the exhaust pipe?

Still need to check the PCV valve but this looks like a right sod of a job since all the inlet manifold etc needs to come off... Is there another way of checking this without accessing the valve directly? I'm considering buying a vacuum gauge in order to check the engine's health.. Will this highlight PCV issues?
Bump?! This is still baffling me! I bought a vacuum gauge. According to a few guides online, when I hooked it up and tested it, everything seemed spot on.


Little Pete

1,513 posts

93 months

Thursday 20th July 2017
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If you had an external leak, that amount of oil would be leaving evidence every time you parked it up. The engine will be burning the oil as you are driving and it is likely to be an internal problem. A compression test will give an indication of how well the compression rings are sealing but it is the oil control rings that could be causing your problem. If these are stuck or worn in any way, oil consumption will be a symptom.

bmwmike

6,918 posts

107 months

Saturday 22nd July 2017
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Conversely I get a small puff of oil / blue smoke occasionally on startup and am actually needing to top up approx 0.1L per 1000 miles or as near as I can work it out. Tiny amount anyway given that it is visible puff of smoke.

Different engine but they all work roughly the same way right.

So surely for an engine to burn .75L per 1000 miles it's interesting that it's not more obvious as to where it is going. Suggests to me it must be burning it all the time in tiny amounts which would suggest rings wouldn't it..?


steveo3002

10,494 posts

173 months

Saturday 22nd July 2017
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think the cat hides /removes the smoke , it has to be burning it

if its passing the mot and running fine id carry on topping it off and accept it

chammyman

123 posts

111 months

Saturday 22nd July 2017
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It will be stuck oil rings on that gen engine always is.

The older ones basically sent its cat back into the cylinders and done the bores.

Wait Here Until Green Light Shows

15,187 posts

199 months

Monday 24th July 2017
quotequote all
The MR2 suffered right up until 2006 with sticky oil control rings and leaky valve stem seals. On the MR2 the oil damages the pre-cat in the manifold, bits eventually break off and get sucked into the exhaust which destroys the engine. I suspect the Auris will meet the same fate if you don't remove the pre-cat.

It sounds like you have this common trait. The amount of oil you're putting in sounds 'normal' if you have the problem.

Howard-

Original Poster:

4,950 posts

201 months

Monday 24th July 2017
quotequote all
It's not the same engine as the 'widely-known' issue that affects the ZZ-series engines - the Auris has the newer ZR-series engine. I can't find anything on Google to suggest that it shares the same design traits. But then that doesn't mean that it doesn't, I suppose...

Is a compression test the only way I'm going to tell whether or not it is worn rings?

chammyman

123 posts

111 months

Monday 24th July 2017
quotequote all
compression test and even a leakdown test won't show stuck oil control rings.

Only disassembly will.

Howard-

Original Poster:

4,950 posts

201 months

Tuesday 25th July 2017
quotequote all
chammyman said:
compression test and even a leakdown test won't show stuck oil control rings.

Only disassembly will.
OK, fair enough. I'm guessing there's no remedying this without disassembly? Different oil etc?

Ballpark cost for repair?

Inline__engine

195 posts

135 months

Tuesday 25th July 2017
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IMO do nothing 750ml per 1000miles isnt worth worrying about on a 1.6 toyota

Wait Here Until Green Light Shows

15,187 posts

199 months

Wednesday 26th July 2017
quotequote all
You could try the old 50% paraffin trick?
Drain oil and refill with a 50/50 mix of engine oil and Paraffin. Run engine at idle till warm (10 mins or so).
Drain, refill with normal oil - run for a few hundred miles and change oil again.

People on UK forums seem to gasp with shock, but it's a common fix in the 'States. I tried it on a Mazda V6 engine and it cured a noisy tappet a treat.