Hi, I recently acquired a Skoda Karoq 1,5 as a lease car. The car was a showroom model and had 14,000kms on the clock. Ever since I got the car I was not 100% convinced everything is in order. The car drives well but I feel it lacks power. The exhaust sounds as though it is partly obstructed and the engine sounds a little muffled as though exhaust is leaking into the valve chamber. I removed the oil cap filler to check for blowback or smoke but there was none, instead I  noticed a strong vacuum in the oil chamber and the engine revved up a little when removing the oil cap. Is this normal? Could there be an ECV problem? A friend of mine has a Seat Ateca also with a 1,5 engine. His car sounds healthier and there is a quicker response on the gas pedal. He is reluctant to  open the engine compartment remove the oil filler cap because the car is not his and is afraid of affecting his warranty. 

 

No engine warning lights

 

Is it normal that there is a strong vacuum when removing the oil filler cap? I read online that when there is vacuum in the valve chamber it could be that the ECR valve is stuck but with just 20k on the clock I find this unlikely.

 

 

 

There is no reason to worry about opening the bonnet voiding the warranty. How else are you supposed to check the oil and top up, or to fill the washer bottle.

Fair enough not wanting to open his bonnet and remove the oil filler cap with the engine running.

 

Leave the Oil filler cap on and only remove with the engine off and to top up the oil. 

 

As long as the friend is opening the bonnet when the engine is up to operating temperature and parked on the flat and the engine off a few minutes.

That is to check the Oil Level before any warning light for Low Oil or Low Oil Pressure.

 

So do you need to check the oil level, cold, then at operating temperature.

 

PS

If there is a Low Oil warning and you open the bonnet, 

the warning can go off for 100 km even if no oil is added.  So be aware of that.

 

 

Edited 22 June, 20223 yr by roottoot

@Routemaster1461 It's not the bonnet he is afraid of opening, just the oil filler cap with the engine running on idle. I have a lot of experience with engines in the past and removed the oil cap on mine, (on idle) just to check for excessive blowback. When the rings or valve seals are worn you get excessive blowback and the engine on my Karoq sounded like engines I had in the past with excessive blowback. Instead of blowback there is a vacuum and the engine is sucking vast amounts of air from the oil filler cap. I don't know if this is normal, I was used to the opposite. Anyway will try and take it to a garage tomorrow.

 

@Roger72What type of engines were these that you did this with?

 

If you think the lease car is not running right then go see a Dealerships technician.

Has the car had a Oil & Inspection Service before you collected it?

 

Is the Ateca the same age as your car and running the same petrol so Unleaded or Super Unleaded E5 or E10?

I opened the bonnet on a previous Yeti about 2000m after its last service to check oil level and refill washer bottle. I found the oil filler cap loose in its housing on the top of the engine. The only reason it was still there was the bonnet above stopping it bouncing out. The car had done all that mileage with effectively no cap fitted with no apparent after effects on longevity. I did about another 40k before it went back to lease company as it was a company provided and serviced car.

I did have oil staining all over the sound insulation under the bonnet and over top of engine though from oil mist escaping.

 

I always check now when I get a car back from servicing that all the fluids are correct and caps fitted properly before driving away.

To investigate, there is no need to completely remove the oil filler cap, just turn it to the point where it can be removed, then pull upwards gently. If there's a little resistance to lifting, that would indicate slight negative pressure in the engine at idle revs, which is as designed (on petrol engines at least).

If there's strong negative pressure resisting removal there's probably something wrong, please let us know what the garage find, if anything.

 

 

Edited 23 June, 20223 yr by Breezy_Pete

Many, if not all cars, have a system to scavenge oil mist from the upper part of the engine. My experience goes back to 60s Minis and other BMC cars, which had a small pipe leading from the rocker cover to the air filter, which allowed mist to be sucked out by a small negative pressure. I remember one instance when my breather pipe got blocked and it caused some issues with oil leaks. Took a while to figure it out.

On 23/06/2022 at 09:27, kenfowler3966 said:

I opened the bonnet on a previous Yeti about 2000m after its last service to check oil level and refill washer bottle. I found the oil filler cap loose in its housing on the top of the engine. The only reason it was still there was the bonnet above stopping it bouncing out. The car had done all that mileage with effectively no cap fitted with no apparent after effects on longevity. I did about another 40k before it went back to lease company as it was a company provided and serviced car.

I did have oil staining all over the sound insulation under the bonnet and over top of engine though from oil mist escaping.

 

I always check now when I get a car back from servicing that all the fluids are correct and caps fitted properly before driving away.

That is a great advice, about a 1.5 year ago we bought my wife BMW and garage did an oil service, when I arrived home I found a paddle occurring under the car, when I opened the bonnet I was shocked - thechician forgot to put a cap on and eft it on the shelf next to wiper mechanism! I had to take the car back to garage next day (minimum of oil in the engine was left) to clean all the oil under the bonnet but it did not help as as soon  as the car was warmed up - oil started evaporating from all hot surfaces, at the end it had to be taken to Main dealer and took about a week to clean, even new bonnet insulation was fitted.

So, the moral is - check all the caps after every visit to garage!