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Matt
Matt, Mechanical Engineer
Category: Car
Satisfied Customers: 22239
Experience:  BEng hons Mech engineering, in auto industry 22 years
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My isuzu rodeo 3ltrs engine managment light comes on and

Customer Question

Hi my isuzu rodeo 3ltrs engine managment light comes on and then goes into limp(no throttal) when this happens I switch off engine,then it runs ok four a short time and then it starts I'll over again!!
Submitted: 2 years ago.
Category: Car
Expert:  Matt replied 2 years ago.
Hello On any car if you get a check engine light or other fault light this typically means one or more of the sensors has failed or has a faulty connection. The fault can be something quite simple and nothing that’s going to stop the car to something quite major that will reduce engine power and possibly stop the engine The ECU sensesthis and may put the car into 'limp home' mode which typically limits the revsand the amount of power available. Usually the car is safe to drive for a short distance as the mode isintended is intended to get you home without incurring any engine damage The quickest route to repair is to have the car plugged into a diagnostic machine which will readoff the fault code stored in the ECU (providing the light is still on at thispoint) and indicate which sensor has failed or whether the fault is more serious. You can do a veryrough and ready check yourself by unplugging sensors one at a time and seeingif any of them change the driving condition which would indicate the mostrecently unplugged sensor is the faulty one. This method is not foolproof though and reading a fault code off is thebetter method.
Customer: replied 2 years ago.
Hi matt,I have allready tried the suggested things that you have said,the auto electrician says there are no faults showing,yet the problem is still there,ie,light goes on pickup goes into limp stop engine restart ok and so on making driving very difficult.
Expert:  Matt replied 2 years ago.
OK so lets try some simple mechanical stuff 1st off replace the fuel filter with a new item as if its only slightyl blocked then this can lmiit powerif OK then check the EGR valve is closing off fully as if its sticking open this will also reduce power check all the highpressure hoses post turbo/s for any split hoses or cracked metal pipes, alsocheck the ends of the intercooler as its not unheard of to pop the end caps offunder high boost. If this is OK thencheck the small vacuum lines to the turbo and its connected control solenoid onthe bulkhead, any cracks or leaks can give turbo issuesAlso have a feelaround with your bare hands with the engine running to see if you can feel anyescaping gas under your touch. Another method is to use a soap and watersolution sprayed onto any suspect areas - if there's a leak it'll bubble upwith the engine running Also check thatthe vacuum hose running to the dump /turbo bypass valve is intact with no leaks as if the dump valve is openingprematurely you'll be losing all your boost If this is OK thenremove the high pressure intake hose after the turbo and have a feel of the turbine wheel - there should be no play radially at all -but a little bit of axial / end to end float is normal one other possibility is that the wastegate actuator spring has gone soft so allowing thewastegate to open prematurely - if youractuator has a threaded end you can increase the preload on it to see if thisimproves things otherwise these units are quite cheap compared to a new turboso it may be worth trying a replacement
Customer: replied 2 years ago.
Thanks matt,I will try this out and let you know.
Expert:  Matt replied 2 years ago.
no problem

just get back to me on this post once you have tried something
Expert:  Matt replied 2 years ago.
Hi

do you still need help?