Is there a "pre heater" in the plastic air intake pipe?

fixhercar · Post by **fixhercar** » 12 Aug 2016, 13:43

My friend took her 2001 s 70 Volvo to a mechanic to have the check engine light reset. She signed an agreement to pay and left the car overnight. It was running fine and she just wanted to know what' the light meant..
The mechanic said that there was a short that was causing the light to go on. You said that there were several components on the same fuse and that they had to disconnect each one to figure out where the short might be. They charged her $270 for the diagnosis and said that the problem was a sorted preheater in the intake tube. They also said that the car wouldn't run because of that fault they replaced the intake tube and charged another $250. So she ended up paying over $500 could get the code checked and the car doesn't run any better then it did when she took it in.

My question is why does this car need a preheater at all and whether or not it would run without the preheater connected?
The mechanic also went out of his way to tell her that her model of Volvo doesn't "age well" and that she will probably have a lot more problems in the future.
I looked at the old oarts, and could see that the "heater" had been pulled off of the plastic tube, by the mechamic, and that it wouldn't stay in place. So that seems to be why the car wouldn't run. Why couldn't he have glued it back in place, and bypassed the unnecessary heater, instead of buying such an expensive redesigned one piece intake tube?

kippster41493 · Post by **kippster41493** » 12 Aug 2016, 15:29

Can't find anything about a pre-heater for those cars, and as for gluing the bit back in. Dealerships aren't allowed to have "rigged" things leave their shop. a.k.a stealership

Klausc · Post by **Klausc** » 12 Aug 2016, 15:39

There is a 'heater'. It is known as the PTC nipple. It is there to keep the oil vapors warm so they do not clog up the nipple. This nipple is not "replaceable", according to Volvo. It is part of the intake hose.

Of course, us shade tree mechanics clean out the nipple as a matter of expediency and thrift. It can be taken off, carefully, and reattached, carefully, but the rubber is soft and it is extremely difficult to get back on properly. Glue will not work.

There is no 'code' for this part. Usually, if it fails and clogs, the PCV system will go positive and the engine will start blowing seals.

Post by **abscate** » 12 Aug 2016, 15:49

That sounds like a nasty mechanic story..

The tube with PTC was a lot less than that when I bought one, too - maybe $100

PS78 · Post by **PS78** » 12 Aug 2016, 15:49

Hi there. I'm wondering if the item you're referring to is the mass air flow sensor since you mentioned a "short". There is a heated filament inside of it that helps the cars processor determine air flow rate entering the intake to accurately meter the fuel mass that is delivered via the injectors. If it isn't working correctly drivability suffers, ie: stalling, no starts, even poor shifting in automatic transmissions. If no improvement occurred with replacement, there is more than likely something else going on. Sounds like parts are being thrown at it without a clear diagnosis, and those prices are way too high also. I'll post a picture of the maf from a 2000 s70 and you can confirm if its the part.