Faulty Actuator Symptoms

[mrwookie]

Fellas,

Trying to diagnose an ongoing issue with my LCR and just trying to rule out the Actuator as being at fault.

I understand that the actuator is controlled via the N75 and in turn controls the wastegate but if the actuator was faulty/sticking would the car boost at all, boost to a lesser psi or would the car try to match the requested psi by increasing the spool of the turbo.....if that makes sense?

My boost gauge shows I'm achieving expected psi but the car is deffo down on power and I can find no leaks externally so wandering if it could be leaking internally via the wastegate?

 

[TubbyTwo]

not sure on the leons, but on my previous turbo cars if the actuator is faulty or weak it will struggle to hold full boost, you wont hit full boost.

these however were all mechanical ones, i assume the LCRs are the same. Usually when the diaphragm or spring gets worn or weaker it wont hold it shut long enough for boost to build up before opening the wastegate.

 

[NottsLCR]

I hope someone can answer this as i have the same issue. No leaks and I changed the N75 and various other parts so now i think it could be the Actuator as when my car was mapped i was told the I wasnt holding boost at the top and it could be the spring in the Actuator?

 

[mrwookie]

not sure on the leons, but on my previous turbo cars if the actuator is faulty or weak it will struggle to hold full boost, you wont hit full boost.

these however were all mechanical ones, i assume the LCRs are the same. Usually when the diaphragm or spring gets worn or weaker it wont hold it shut long enough for boost to build up before opening the wastegate.

Superb thanks.

Would be be feasible to say though that if my actuator was knackered and the boost started to build that the wastegate could be forced open if the actuator is unable to maintain the pressure to keep it shut and therefore cause the car to overboost to try to compensate???

 

[TubbyTwo]

Superb thanks.

Would be be feasible to say though that if my actuator was knackered and the boost started to build that the wastegate could be forced open if the actuator is unable to maintain the pressure to keep it shut and therefore cause the car to overboost to try to compensate???

again not 100% sure on the LCRs but i would think it would be the opposite mate, if the spring in the actuator was weak it would open too early and open the wastegate too early, so you would stuggle to make high boost.

If the actuator was jammed shut your boost would continue to rise, and then you would overboost. So in effect if it was jammed shut the boost would just keep increasing.

 

[mrwookie]

again not 100% sure on the LCRs but i would think it would be the opposite mate, if the spring in the actuator was weak it would open too early and open the wastegate too early, so you would stuggle to make high boost.

If the actuator was jammed shut your boost would continue to rise, and then you would overboost. So in effect if it was jammed shut the boost would just keep increasing.

Im getting myself confused i think... but the 1st thought may ring true with mine. You think of way of testing this...??

 

[TubbyTwo]

on my MR2 to test the actuator i connected a foot pump to the inlet of the actuator. then pumped it until it until it was up to pressure and opens the wastegate. the gauge on the foot pump will show you the PSI then.

again tho on LCRs i dont know what electrical parts are involved in the turbo system.

just remember tho that if the actuator is weak (usually) you wont hit full boost as it wont be able to remain shut long enough to build up the pressure to open the actuator.

If its jammed shut you will build up too much boost as there is no way of opening the wastegate to lower the pressure and bring the boost under control again.

 

[robertbadlad]

where is the n75 thingy?

 

[wild willy]

Its easy to test, connect a pump and measure the psi it begins to open at and the psi that causes maximum arm movement. A stock lcr will initially operate at approx 5 psi and full opening will be achieved by 10 psi. Its very rare for an actuator on an lcr to cause problems. Lets see some vagcom logs Mr Wookie to see if we can't help you find your problem.

 

[JEFFERY CRUZ]

Symptoms should always be put into their correct category. They should also be put in alphabetical order unless there is a logical reason not to .
If you are unsure whether a condition is a disorder or a symptom (i.e. a cause or an effect) please list it here on the talk page so it can be verified.

 

[JEFFERY CRUZ]

I don't really seen why this page is necessary, especially if ICD-10 codes are listed. Why not just use the List of I realized that this article might be much shorter and only contain generalized symptoms as opposed to all the diseases in the article I just mentioned, but I feel like this article is the nonetheless gratuitous.

 

[seatcupramad23]

was it holding boosdt b4 remap ? on the lcr as standard they shud boost up about 14-15psi then hold at about 10-12 depending on the whether, cause i had the same isues on my lc boosting fine b4 the map 12 psi n holding between 9-10psi , after the map it was hitting 18 psi then not holding at all drop to about 11 psi turn out to b turbo n der was no usual white smoke symptoms

 

[seatcupramad23]

mayb wise to just buy a forge actuator , sadly the more parts u change the nearly u get to solving the problem, im suprised they even mapped ur car n sent u on ur way with the car not running right :s

 

[robstevens]

Hi can anyone help i have a leon cupra It will boost to 17-20 psi then it will stop and only go to 5psi turn engine off and on and it will reset and be fine