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Mike Kelly
Mike Kelly, Auto Service Technician
Category: Car
Satisfied Customers: 5471
Experience:  17 years experience as an auto mechanic, foreign and domestic. 5 years running my own repair business.
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Hi I have a 55 plated nissan primastar and recently two things

Customer Question

Hi I have a 55 plated nissan primastar and recently two things have raised their heads with this vehicle.
Firstly when the engine reached 1800 revs it sounded like there was a hole in the exhaust, it sounded like when you take the air filter off of the top of a carb and rev it ( throaty sound). My mechanic did a smoke test and found a split at the end of the intercooler pipe engine end. Fairly cheap fix using self amalgamating tape. Then day later driving on the motorway 65ish in 6th same sort of sound came into play revs were at around 2600 let foot of slightly and loud rough noise was heard this continued right down to 2000revs. In this range you could call for more power and the noise would go but would come back but not every time intermittant to say the least.
Any advice and answer would be greatly recieved.
Submitted: 4 years ago.
Category: Car
Expert:  Mike Kelly replied 4 years ago.
Hi,my name is mike and I will assist you with your question?
The issue that you are describing and the way that this happens is consistent with a exhaust flow issue that is trying to choke the vehicle out. The first step that I would suggest is to have the glow of the exhaust checked and to have the entire exhaust checked with a heat señor to see if it is above temperature,this would be caused from a restriction and sending back pressure to the engine and causing the issue.
Customer: replied 4 years ago.

Hi Mike, thanks for your info, i assume the engine will have to be at full running temp. The heat sensor you mention, is this something that can be done at home over a pit or only something that a garage has to do. With all the probs that i seem to of had are they related to the induction side or is it a case that one thing is fixed and another shows itself.

Cheers dave

Expert:  Mike Kelly replied 4 years ago.
It's a case that one is fixed and another shows itself. It can be done at home however it would be cheaper at a shop because the heat sensing gun is expensive.
Customer: replied 4 years ago.

Cheers mike, what sort of temp should we be looking for along the exhaust? Not to say you could be wrong with this as i do understand you dont have the vehicle in front of you, but if all comes back from the garage with normal temp what else could it be? Sorry to be so negative but i have had no luck with motors since i had my first car.

Cheers Dave

Expert:  Mike Kelly replied 4 years ago.
The exhaust should be around 1600F and if the exhaust checks out fine I would look in to the fuel system at the fuel pressure looking for the pressure to be bleeding off. Also you can respond back to this question at anytime after rating and I will answer any further questions you have.