Engine oil flushing & boot hole repairing.

B0bbyEwing

ENGINE FLUSH:

Bought a 2005 1.3 Yaris. Came with not full but quite a lot of service history. 50k miles. Original owner had it for 19 years & then it changed hands twice within the next year before coming to us. Original owner kept a lot of records it seems but from what I can tell it's not had an oil change since 2024 so it's certainly due. I can see the oil filter & it looks fairly tired.

I've previously read about using engine flushes & how they can do more harm than good.

Also read about an alternative approach being using cheap oil, run it for 15-20mins, drain it & then put better stuff in.

Recommendation is 5w30 but have read about using something like 10w30 / 15w-40 (these specs are in the manual) for the cheap flush as it'd work better than 5w30…allegedly.

I actually have various old canisters around of 5w30 though from previous oil changes where if I pool them together I may end up close to the just shy of 4ltrs required.

Which brings me to my question - would that be detrimental in any way, since it's only being ran for 15-20mins? The oil would be minimum 1yr old up to a few yrs old, but unused.

Side questions - whether this is ok or whether I should just buy some brand new oil to do this, do you also slap on the cheapest filter you can find for this step or use the existing one?

When they say run it for 15-20, I assume we're talking just leave it sat there idling, stationary & not actually doing anything as far as driving / getting revs up?

BOOT HOLE:

Seems to be a common fault with these Yaris's - wet boot.

Problem is, between the previous owner & the garage they took it to, someone in their infinite wisdom thought it would be a good idea to drill some (3mm-ish at a guess) 'drain' holes in the floor of the boot underneath the spare wheel.

Now I'm not the most mechanically minded of people but if water is passing one way through a hole then it can pass the other way too. Not only that but on a car known for rust (thankfully this doesn't seem to be bad for it) you've now just left bare metal mixing with water.

Why not instead have a look at the likely causes … such as rear light cluster gasket.

Anyway, enough of a rant there but what'd be the best approach to tackle that?

Obvious one is blobs of silicone but I imagine that's probably not the best approach.

My plan was when the weather turns better, to give the underside a good scrub & clean & then throw something along the lines of Lanoguard at it, the whole underside & now also the boot.

I want to sort it in terms of water coming in from them holes & also protect against rusting.

sheenas

would never use flush as it can cause problems by dislodging dirt. I aways keep to the recommended oil and a good filter.

regards the wet boot would look an owners forum as see what they recommend.

Bigwheels1111

WOW a lot to think about.

I ran Rover diesels for 200k miles cabbing them never did an engine oil flush.

No issues at all.

I would not bother, I would change the oil and filter for sure.

Change now and again in say 3 months, if you want.

Check air filter and pollen filters if fitted as a lot of people do not bother to change them.

Are plugs due, if so use denso plugs

Re Boot, this is a common fix, Drill hole spray with hammerite and your done.

Rovers always had water in boot, a leaky side vent behind the bumper, remove bumper, drill out rivits,

remove vents, reseal with loads of silicone and new bolts, to much like hard work.

Drill holes.

facade

The oil, I'd do as you suggest, and run it on all the oil that you can find for half an hour or so.

If you have enough to get it above low on the stick, you can drive it around for a while, otherwise just let it tick over. I'd fit a reasonable new filter, then change it for a quality one when you put the correct oil in. (Hopefully there is nothing in the oil, but if there is debris in the oil you want a filter that can catch it) Removing the sump and cleaning it out would be a good idea if it is easy. Give the outside a clean up and paint with metal paint.

Unlike some cars, Japanese cars tend to keep the oil inside the engine, so the sumps rust from the outside in.

The boot, I'd clean around the holes to remove any rust and then paint with some of that metal paint. I'd likely duct tape over them then if the boot does fill with water you can lift the tape.

Lights, I don't know. New gaskets would probably be the way to go, I've tried using masses of silicone sealant on old gaskets and it never ever works.

Lanoguard, I wouldn't as I heard that it can attract vermin to come and chew wires and cause problems.

Spray with one of the Magic Fluids made by Dinitrol instead. The rear axle beam and front subframe are known for rusting, best to get the wirebrush to anything crusty and then daub with that metal paint before you spray the dinitrol.

paul_c123

There needs to be a reason to flush an engine. What you describe isn't actually flushing though, because flushing uses an oil of significantly lower viscosity and higher detergents. What you're doing is 2 oil changes instead of one. In your specific example of using cheap 15W-40 instead of correct 5W-30 grade, it is impossible to give proper advice without also knowing what temperature you're doing at (because oil viscosity varies with temperature), but its likely the 15W-40 is never a higher viscosity (and probably very similar) in your 15-20 min run, than 5W-30 during winter.

It would actually make more sense to keep the 15W-40 in for a week.

clive0510

I used to be in the motor trade but retired now. I'm not sure 5w30 is correct oil for that car.

so best thing to do is get it to a toyota dealer and find out what the correct oil is. also get a price for them to do it.

also enquire if this is belt or chain driven engine. if its a belt does it need changing. its a big job.

I think there was a problem with leaky boots on these cars, so ask if there is a recall and if its covered.

the above points are probably why its changed hands twice in a year.

dont bother with engine flush. you just end up disturbing stuff you didnt need to.

Alanp

re the boot holes, drill them out a bit then put blanking grommets in, the type electricians use to blank off metal back boxes, then you can remove them easily if you need to drain any water off..

B0bbyEwing

https://forums.moneysavingexpert.com/discussion/comment/81906749#Comment_81906749

Not really a lot. It's an oil change & a boot hole repair really. 2 things.

also "drill hole……..and you're done"? That's accepting water coming in rather than bothering to fix the issue & stop water coming in.

Also, it's most certainly not done because the holes have been drilled & the water is still there & the carpeting is soaking.

https://forums.moneysavingexpert.com/discussion/comment/81906762#Comment_81906762

Thankfully we don't really have a mice issue here where I live (more of an in-house rat issue unfortunately). There'd be more at my previous house but my brother uses Linoguard on his stuff there & has had no trouble that way. I accept what you're saying though.

Interesting on the light gasket though as I was considering either some silicone approach or that liquid gasket stuff. It made me wonder though - what about when you need to change a bulb? The light unit is then bonded to the car unlike a normal foam gasket.

Thanks for the tips though.

https://forums.moneysavingexpert.com/discussion/comment/81906796#Comment_81906796

To my know-nothing mind, what you say makes sense. Thanks. May be an approach to take.

A weeks use for the OH would probably only be about 30 miles over 5 days, ish. The coolant may get to temp but the oil likely wouldn't as she's only doing short journeys - hence us getting rid of the diesel for a small petrol.

https://forums.moneysavingexpert.com/discussion/comment/81906844#Comment_81906844

I thought I made it clear in the OP that I wasn't going to do an 'engine flush' in terms of chemical flush - as I said I read they do more harm than good. Seems a few responders think I was considering the chemical approach so to clarify - I'm not.

Also, you do say that you're not sure if the oil is correct so that's fair enough rather than saying it's not. I can assure you though that it is. Either that or the cars own manual is wrong, one or the other, because that's where I got the info from. The manual states the grades I mention in the OP can be used but 5w-30 is the advised one.

And I would never get a dealer to do an engine oil change ever. I wouldn't even get my backstreet garage to do it. There's limited things I can do on a car but filter changes are one of the things I can. Belts I don't (this is a timing chain apparently btw).

https://forums.moneysavingexpert.com/discussion/comment/81906881#Comment_81906881

This is actually what my brother said to me. I wasn't sure if he was being daft. lol.

Mildly_Miffed

Just 50k miles in 21 years, with a full history and plenty of services… but the oil in it might be 2yo - and you're worrying about flushing it?

Just change it and drive the poor thing more.

As for the holes. I'd personally drill them out a bit larger, then fit rubber grommets. Paint the edges properly after doing so, and a bit of wax around the lip of the grommet.
5 x 6mm rubber blanking grommets, change from £2 delivered.
https://www.ebay.co.uk/itm/262281562555

B0bbyEwing

It always baffles me as to why when asking something people assume you're worrying.

But anyway, I'll look in to that rubber grommet approach. Thanks.

fatbelly

Check you don't already have rubber plugs in the boot. Someone told me there were three in my Roomster. I said there wasn't . When I checked, because they were painted over they just looked like part of the floor under the spare wheel. As they were quite large (say 2 inches across) i decided against removing them but did put holes in them so any water can drain out.