Hey all,
I'm at an impasse with my car and I figured I'd try see what you folks (by far the best problem solvers for my Volvo) thought might be the cause of my problem.
The car is a 1983 240 Turbo. It's an automatic with 3spd+OD (I am told this was a common mod).
About a month ago I had the timing belt snap at very low speeds. The car just died and, since I was going about 5km/hr I was able to coast to the curb and wait for a tow. The belt was replaced and I was on the road again. The day I got the car back I took it for an oil change and decided to try something new: 20W50. Before you punce on this hear my reasoning: the car temperature has been higher than normal (a little higher every summer) and at one point on the third of several consecutive really hot days the 10W30 seemed to completely break down, registering low oil pressure even though the dipstick said it was ok. After consulting the manual (and checking here) I decided to take a shot at the 20W50 and put it in the day my car came back from the belt replacement.
I mention this because I can't be sure which of these two factors is causing "the noise".
The noise is best described as a METALLIC GARGLE, not unlike the sound large trucks make. It comes in when the engine is under a load, either uphill or accellerating. The sound comes in right when the Turbo boost hits the yellow but if I push through that it goes away again and the normal whine of the turbo spooling up can be heard. Also this sound is coming from the back (or, I suppose, out of the exhaust). Also there might be a little less power than before but things are otherwise normal. If I can drive VERY conservatively I can avoid making this noise most of the time.
One final tidbit: I have been topping up the oil with 10W30 as needed and it has had some effect but has not completely eliminated the noise.
My biggest fear: the Turbo bearings or some key engine component is damaged either by thick oil or the snapped timing belt. Ruled out: the exhaust has been thoroughly checked.
Any ideas?
Thanks in advance, Boris ps. Somewhat related: I got an antifreeze tester and it tells me what temperature I will freeze/boil at. This seems completely disconnected from the units specified in the manual...what range should I want to see? How do I know whether to add water or antifreeze?