2002 Toyota Corolla ZZE121(H) Engine idle problems

[Speil]

Hey, my 2002 Toyota corolla 1.6vvti has an idle problem. When i cold start, it revs up to 1500 rpm but when it warms up it goes down to 700 rpm.

I have no idea what it can be, but i have been thinking that it might be a sensor.

I have replaced the air filter, spark plugs, oil filter and the oil. I haven’t checked if there are any fault codes, but there is at least no one on the dash.

Also think i got a very small oil leak on the far far end of the passenger side (for me it’s the right side). It’s almost like it’s right behind the wheel, but more towards the front.

 

Thanks for any advice/suggestions!

[oldcodger]

34 minutes ago, Speil said:

When i cold start, it revs up to 1500 rpm but when it warms up it goes down to 700 rpm.

That sounds perfectly normal, exactly what mine has always done.

A rich mixture to get it running while cold then as it warms up the mixture become normal and the revs drop to a normal  tickover.

Ours often hovers around 600 - 650rpm  and its known that at such a low tickover it can feel a little lumpy and you can feel a bit of vibration around the car.

 

37 minutes ago, Speil said:

 

Also think i got a very small oil leak on the far far end of the passenger side (for me it’s the right side). It’s almost like it’s right behind the wheel, but more towards the front.

Thats a little more concerning and needs to be checked thoroughly and quickly.

It could be various things, a leak on the brake pipes or petrol pipes,    possibly the shock absorber leaking ?

 

Assume the car is new to you ?

[Speil]

1 hour ago, oldcodger said:

That sounds perfectly normal, exactly what mine has always done.

A rich mixture to get it running while cold then as it warms up the mixture become normal and the revs drop to a normal  tickover.

Ours often hovers around 600 - 650rpm  and its known that at such a low tickover it can feel a little lumpy and you can feel a bit of vibration around the car.

 

Thats a little more concerning and needs to be checked thoroughly and quickly.

It could be various things, a leak on the brake pipes or petrol pipes,    possibly the shock absorber leaking ?

 

Assume the car is new to you ?

Does yours have a steady idle? Or keeps “jumping” up and down? Mine jumps up and down, not much but enough to notice it.

I haven’t noticed anything wrong with the brakes, and the reservoir seems fine. And i’m pretty sure it’s not petrol related. It might be the shock absorber, since it’s stock from new. But i honestly think it’s from the engine. I have a picture from the rear side of the engine. I’ll put it down below.

The thing is that it doesn’t look like it’s leaking much.
The car is fairly new to my ownership's, but it has been in my family since new. Also the car i learned to drive with😂

[oldcodger]

The tickover revs can be up and down a bit, though you might want to try cleaning the throttle body to try and improve things, examples on ytube.

That oil leak is not good, probably the cam cover gasket or the chain tensioner ; you need to clean off the old oil to see exactly whats leaking.

Note that the cam cover gasket also needs some sealer when fitting  - see diagram, possibly the sealer  has failed, which is near where your leak seems to be ?

 

 

[tfc]

It's normal to rev high when cold if it didn't  there's  a good chance it would be popping and farting till the engine gets up to normal temperature. 

Before electronic ignition old cars with carbs had a manual choke knob which you pulled out to aid starting from cold  what it did was close off the air inlet to richen fuel air ratio and give it a faster idle and as the engine started to get warm you would shove the knob in a little at a time as the engine temp got warm, and later some carbs had automatic choke which worked off the temperature of the coolant system.

[Speil]

On 12/20/2023 at 12:30 PM, oldcodger said:

The tickover revs can be up and down a bit, though you might want to try cleaning the throttle body to try and improve things, examples on ytube.

That oil leak is not good, probably the cam cover gasket or the chain tensioner ; you need to clean off the old oil to see exactly whats leaking.

Note that the cam cover gasket also needs some sealer when fitting  - see diagram, possibly the sealer  has failed, which is near where your leak seems to be ?

 

 

To me it seems like it’s the head gasket? It starts right where the chain tensioner is. Either way it seems like the chain tensioner is leaking. But another question, sometimes i get the low oil light even though i have the right amount of oil in the car.

I have to change the oil, but can it be due to it being old/clogged oil filter?

I looked after a new chain tensioner online but couldn’t find any available. Is it possible to just change the o-ring? I also checked with some local parts stores + dealerships and no one has it in stock…

[oldcodger]

39 minutes ago, Speil said:

To me it seems like it’s the head gasket? It starts right where the chain tensioner is. Either way it seems like the chain tensioner is leaking. But another question, sometimes i get the low oil light even though i have the right amount of oil in the car.

I have to change the oil, but can it be due to it being old/clogged oil filter?

I looked after a new chain tensioner online but couldn’t find any available. Is it possible to just change the o-ring? I also checked with some local parts stores + dealerships and no one has it in stock…

Would first change the oil and filter and see if that makes any difference to the Oil Light.

The Oil pressure switch is located just above the oil filter so worth checking the wires / connector are sound.

The cam cover can leak oil over that same location as when its fitted it needs some Silcone Sealer to bridge an area in that same location,  so if the sealers perished it could also be that.

Think our cam cover or tensioner is also leaking , but just a very small amount.  Surely Toyota can order you up an O ring ?  if your local dealer will not do it, then go to the Toyota eBay store and ask them for a price.  just mention the part  along with your Reg and Vin numbers.

You can buy large assorted sets of O rings on eBay quiet cheaply,  more than likely one would fit ?  If you do remove  the tensioner, it states you should not rotate the engine at all when its removed.

As for the head gasket, possible but unlikey if you are not getting other associated problems.

Do you have hydraulic power steering which was located in that same area near the tensioners ?

 

[Speil]

1 hour ago, oldcodger said:

Would first change the oil and filter and see if that makes any difference to the Oil Light.

The Oil pressure switch is located just above the oil filter so worth checking the wires / connector are sound.

The cam cover can leak oil over that same location as when its fitted it needs some Silcone Sealer to bridge an area in that same location,  so if the sealers perished it could also be that.

Think our cam cover or tensioner is also leaking , but just a very small amount.  Surely Toyota can order you up an O ring ?  if your local dealer will not do it, then go to the Toyota Ebay store and ask them for a price.  just mention the part  along with your Reg and Vin numbers.

You can buy large assorted sets of O rings on ebay quiet cheaply,  more than likely one would fit ?  If you do remove  the tensioner, it states you should not rotate the engine at all when its removed.

As for the head gasket, possible but unlikey if you are not getting other associated problems.

Do you have hydraulic power steering which was located in that same area near the tensioners ?

 

Will do! Im going to change it on monday, so i might just find out the side and buy a o-ring set! I will take a look at the connector when i’m there anyway! 

I will take a look at the cam seal, but do you mean that there should be a silicon seal in the same area as the chain tensioner?

I think i have hydraulic power steering. Some form of power steering is there. I have to turn on the engine for it to activate.

About the head gasket: I have checked under the oil cap, and there was some white/brown residue it wasn’t much just a little layer on the top, but it could just be condensation. I removed it and there is kind of a chocolate milk color stuck to the cap. But i will check regularly for a few weeks to see if it gets worse or it’s the same. I also topped the coolant of, reservoir was almost empty. Put about 1.5L in (reservoir and radiator).

Sometimes it also seems like it’s not giving enough power. Sometimes it drives very well, and gets up to speed as expected without any “lags”. But there are times where it’s struggling to get up to speed, it feels almost like a turbo, like it gets a boost around 2500-3000 rpm. When i shift its the same over again.

You have any idea there? 

[oldcodger]

Hi,

Not sure whats what here ?

Your opening post said you had changed the oil and filter, recently ?  but now looking to do it again ?  Also your pics of the oil on the floor does not look like fresh oil, more old used ?

Initially it was just about idle speed, now it seems you have a possible water leak or as you say head gasket problem, yet you only now mention it has a power problem as well .

When you replaced the spark plugs, did the electrodes all look the same colour or were some different ?

Is the car new to you with an unknown history  ?

Sounds like you need to do a visual inspection of the water works, its easy to miss a leak on the front side of the radiator or under the water pump.  If it all looks intact then  probably the best thing is to have a water pressure test, you can buy such kits online or a garage can do that for you,  Lots of ytubes on how it can be done diy.

[oldcodger]

Just giving ours a fluids checkover etc and gave it a closer inspection of  our leak,  viewed from above the engine  its clear to see it coming from the cam cover just above the drive belt tensioner.

Its only a small weep, but can see if it was a larger leak it would probably run down  onto the chain tensioner, so worth another look from above to make sure its not the cam cover gasket.

If its the Chain tensioner O ring, seems they are around separately under the code 90301-22013, so probably worth getting the right part from Toyota.

The Toyota eBay * site lists parts it has so far supplied, and its not one of them, so contact them and ask for a price, probably less than any postage.

* if you are in the UK  ?  though any Toyota dealer should be able to order the part for you, whatever the country.

 

[Speil]

19 minutes ago, oldcodger said:

Just giving ours a fluids checkover etc and gave it a closer inspection of  our leak,  viewed from above the engine  its clear to see it coming from the cam cover just above the drive belt tensioner.

Its only a small weep, but can see if it was a larger leak it would probably run down  onto the chain tensioner, so worth another look from above to make sure its not the cam cover gasket.

If its the Chain tensioner O ring, seems they are around separately under the code 90301-22013, so probably worth getting the right part from Toyota.

The Toyota Ebay * site lists parts it has so far supplied, and its not one of them, so contact them and ask for a price, probably less than any postage.

* if you are in the UK  ?  though any Toyota dealer should be able to order the part for you, whatever the country.

 

Hi, im sorry! Seems like i have done a mistake! What i meant to write the first time around was that i had been told it wasn’t long since the oil was changed. I’m sorry about that!

Anyway here’s what i have figured out today. There is no leak from the coolant, everything seems fine there and under the cap.

The oil is still the problem, but i will have a look at the cam cover, and the o-ring. (I’m not from UK and english is not my first language. So again i’m sorry for my mistake when writing!)

I drove for about 1 hour today to visit family, and the oil light started to turn on. I looked at another post named “E120 2002 1.6vvti low oil pressure” where the oil pipe is clogged, with the same symptoms as i had today. So i think i’m going to buy a gasket and just clean down there, when i first are going to change the oil!

Btw the spark plugs seemed fine, no other signs than normal use.

Thank you for the help so far! I’m sorry if i don’t communicate on a good level.

[oldcodger]

On 3/8/2024 at 11:15 PM, Speil said:

 

I will take a look at the cam seal, but do you mean that there should be a silicon seal in the same area as the chain tensioner?I

No, the Sealer is just used on the Cam Cover as in this picture.

Loosing 1.5 ltrs of water is a lot, would keep a close eye on it level.

A water pressure test no only helps find a leak in the pipes and radiator but also the cylinder head gasket.

The other likely cause of such a water leak is from the Water Pump which has a drain hole on the underside so if its bearing /seals start to fail you see traces of antifreeze around it.

 

Before doing your Oil and filter change, it might be worth using an Oil Flush addative to help unblock any oil ways etc, a lot easier than removing the sump cover .

Expect you will have one of these products or similar  in your country.

https://www.parkers.co.uk/car-advice/car-care/the-best-engine-flush/