The smell of burning rubber

[wayland]

Hi there folks,

This is my first post on this forum so this is an intro as well as a question. Before I get to the question I will give you a little bit of info on myself. I have been working in the metal industry for nearly thirty years. During that time I have made many different parts for many different things ranging from parts for missile guidance systems that would fit on your little finger nail up to mezzanine structures that cover many thousands of square yards.
I have of course made many parts for the auto industry including light units, pedal assemblies, brake components and much more besides. If you are driving a 2000-2002 Toyota with an electronic accelerator, the chances are that I made the tools that welded it together. So that's my claim to fame. Now for the question.
I am now the proud owner of a 1993 Toyota Previa GL 2.4 petrol automatic with 250k KM on it in pretty mint condition. But...I can smell burning rubber when I get out of the car. There doesn't appear to be any strange noises and I can't locate where the smell is coming from. It's not the tyres, (I don't drive that fast these days) I was wondering if it's possibly the SADS as this seems to a common fault on the Previa. Can anyone tell me if the smell of burning rubber is a symptom of a failing SADS.
Yours hopefully Wayland.
P.S. congratulations on an excellent forum.

[timsrv]

Hello & welcome! I too was once a tool maker (aircraft industry) . Nothing immediately comes to mind regarding "burning rubber" smell, and SADS issues are usually detected by sound or vibration. Is it possible you are smelling burning oil? Valve cover leaks are a common issue with the Previa. There is heat shield between the exhaust header & the valve cover & that can act as a gutter. Oil drips onto it, then runs to the back. There is a hole in the back of the shield right above the "collector" area of the header, and that is typically where the oil drips when you stop. If your parking spot is on an upward slope, this can allow more of the oil to drip. This is the 1st place to look. If that heat shield is wet with oil then you'll need to replace the valve cover gasket. Be sure to use a dab of FIPG (Form In Place Gasket) in the corners of the distributor boss. I like Toyota's FIPG (available at any Toyota dealership) as I think it's superior to silicone. It costs about $10 per tube (at least here in the USA). I hope that's it. Good luck. Tim

PS: There's an access panel in the floor above the valve cover. Assuming your Previa is a LH drive, remove the passenger seat and peel back the carpet 1st. After that it's all self explanatory.

[wayland]

Hi timsrv,

You may well have a point. I checked under the van and saw some oil from the cover. I will investigate and repair asap. The smell may well be oil, I recently gave up smoking and the whole world smells weird at the moment.
Glad to meet a fellow tool maker.
Regards, Wayland

[pdgizwiz]

Wayland-
Here's a link to an older thread that describes the issue. A whiff of bunt oil as you exit the van is the tell-tale.

The valve cover gasket turns to glass in time, then it cracks and leaks. Toyota saw this coming and designed an external combustion system!
While you're doing the gasket, do the O-ring behind the distributor at the same time. Chances are it will come out in pieces. The PVC grommet and hose are available and easy to swap with the cover off as well, and the PVC valve itself is too cheap not to replace at the same time.
The gasket often comes with a set of spark plug tube seals, so those can be renewed as well. In general, my philosophy is that anything rubber that's seen fifteen years of engine temperatures stands to be replaced.

I've no aircraft experience, but if you've had an ultrasound exam, it's possible that I had a bit to do with the equipment your doctor used.

Paul

[wayland]

Thanks Paul. I will do that very thing. I will be going to the main dealer later this week and will get the parts you suggest. Nice one brother.