[Ferv]

Hiya guys. Have a bmw individual msport 528i 2016.

The heater doesntnreally blow out hot air, a few weeks ago on a long early am drive, the car even fogged up. It's still blowing out plenty of air, but just not hot hot. The car gets to a reasoanble tmep most of the time, but still nothing hot from the front vents. Mainly slightly warm from the windscreen vents.

I also stage 1'd the car woth a software tune about 4 months ago. And when driving enthusiastically, around mountains etc, I notice a strong burning kind of smell, almost rubber, but sure it's not the tyres.

Any advice from you good people?

Clay

[95blkmax]

NO HEAT- a few things can cause this. Before mentioning that though, I do suggest you try to bleed the coolant system,. It's very easy and it often fixes the issue. If bleeding the air did not fix it, then you have a few possibilities. A faulty heater control valve (inside engine bay, along the left side frame rail, has 1 hose going towards the front, and 2 going to the firewall). This is what controls flow to your heater core. If it fails it will be stuck in whatever position it was in at the time of failure. Also, a faulty HVAC box flap actuator. You have about 10 actuators moving flaps that control where air goes and how much cold/ hot air gets to these passages. If the flap that controls hot air movement is stuck, you wont get any hot air. Both options you can check with ISTA+ and it has test plans for the IHKA (climate control panel/ module) and it will test functions on all flaps and circuitry of the IHKA system.

BURNING SMELL (if rubber)- Check your belt and belt tensioner. I assume you have an N20 engine? They are known for belt and tensioners wearing out much faster than other BMWs. The fact that you only smell it when driving spiritedly and that N20 history points me to check that first.

BURNING SMELL (if oil)- two likely culprits which plague all BMWs- oil filter housing gaskets (which if these are leaking, this oil will also get on the tensioner and belt... if so they'd need to be replaced in conjunction with the OFHGs). Also, valve cover gasket. This leak's oil will get on the exhaust heatshield and burn. A typical spot to check on N20s is at the back where the vacuum pump bolts to the VC. Even if the VC gasket itself isn't leaking, it's possible that the vacuum pump is (has it's own circular seal). But to replace that, you have to pull off the VC... so you might as well do the vac pump seal along with the VC gasket job).

[Ferv]

Thanks mate, this is brilliant. I'll check these things and get back here in a few days once I've done this. Hopefully it's just a coolant flush fingers crossed!