Edmunds dealer partner, Bayway Leasing, is now offering transparent lease deals via these forums. Click here to see the latest vehicles!
Stump The Technicians--Contest Rules Are Here!
Mr_Shiftright
Member Posts: 64,481
Okay, this little game is meant to challenge all our Town Hall technicians (amateur and pro) diagnostic skills. Here are the rules, everyone can play:
1. Describe the symptoms of a real problem you solved or had solved, but don't tell us the answer right away--just the symptoms of the "puzzle"
2. Let us come up with answers and the reason why we think we are right.
3. Stick to problems that had definite, solid answers, not "and they fiddled with some wires and it went away". Those aren't very satisfying.
I'll start off in the next response to give you an idea of what I think would work.
best,
Mr. Shiftright
Host
1. Describe the symptoms of a real problem you solved or had solved, but don't tell us the answer right away--just the symptoms of the "puzzle"
2. Let us come up with answers and the reason why we think we are right.
3. Stick to problems that had definite, solid answers, not "and they fiddled with some wires and it went away". Those aren't very satisfying.
I'll start off in the next response to give you an idea of what I think would work.
best,
Mr. Shiftright
Host
Tagged:
0
This discussion has been closed.
Comments
Friend calls me up, asks me what to do. I tell her to pull over until car cools down, then come over to see me (she is very close). She does this.
I open the hood and notice that the coolant overflow is FULL. Temp gauge is in the red but not all the way. I see NO LEAKS. The electric cooling fan is cycling on and off every 30 seconds, but the temperature will not drop, nor will the fan stay on longer. The engine feels pretty hot to touch but is not steaming nor does it smell overheated. I couldn't check the radiator coolant level for obvious reasons. I did check all fuses and they are fine. Belt driven fan was turning, and fan clutch operating.
QUESTION: What has happened to this car?
ANSWER: The answer, which explains all these symptoms, can be stated in under 10 words, even under 5.
So not the right answer, but a good answer nonetheless.
Are we allowed to ask questions that will further enhance our understanding of a problem?
My guess about the 1999 325i is that the engine was not actually overheating. Instead, I think that there was a problem with the Temperature Gauge or its sensor.
If I can ask a question: what did the gauge show after a cold start, and after 5 minutes of operation?
Best Regards,
Shipo
Unfortunately, my days of turning a wrench are mostly over (at least for now), and I am unfamiliar with the specifics of the BMW I6 (even though I drive one myself). So, if the above guess is incorrect, I will have to demur to others more knowledgeable.
Best Regards,
Shipo
As it turns out it was not the water pump, so my decision to exclude it was a good one. I could not verify pump action because I dared not open the radiator at this time.
All you have to do is cut and paste your post and save it until we're done with this one. You should also delete your post for now.
thanks,
Shifty
Best Regards,
Shipo
Best Regards,
Shipo
Best Regards,
Shipo
That's a fancy way of saying I like shipo's answer. :-)
But thinking about the sensor did lead me closer to the problem, that's true.
After the car cooled down, I opened the radiator to find--very little water! This would explain why the sensors wouldn't read properly (sensors don't read steam or air very well). But there WAS some water in the radiator.
Soon found a crack in the upper radiator outlet, but the hose was partially obscuring this crack. I guess the water had slowly leaked/steamed out but once pressure was relieved the rest of the water in the radiator just circulated as if it were a non-pressure system.
So mainly I was fooled by thinking that because the coolant tank was full the radiator was full. I should have realized with the crazy sensor behavior that the radiator coolant was very low. This was also why the fan could not bring down the temperature.
OKAY--NOW FOR SHIPO'S QUIZ?
In 1988, I visited a family member who I saw about once a year back then. He and I were sitting around his back yard drinking a brew when he mentioned that his motor home was having a problem that prevented it from traveling faster than 35MPH, only when the engine was warm. The vehicle in question was one of those motor home vehicles built on a full size Dodge Van chassis with a Dodge 360 CID engine, I cannot remember whether it had a 2 BBL carb or a 4 BBL one.
The exact symptoms were as follows:
-The engine would start easily from a cold start.
-After the cold start, the vehicle ran just fine at all speeds for a few minutes until the engine warmed up.
-Once the engine was warmed up, it would idle with no apparent problem.
-From a standing start, the engine would run fairly well in first gear, however once second gear had been engaged, the whole vehicle would start bucking and shaking with terminal velocity somewhere in the neighborhood of 35MPH.
He also told me that he had had it back to the dealer who was unable to diagnose the problem, and had even taken it to a friend who was a Chrysler Technician, who was also unable to diagnose the problem. Given that this person had a very large EGO (and I was about 20 years to his junior), I was reluctant to offer my help, however, after the third time he brought the subject up within the span of one hour, I suggested that we take a look.
We opened up the mini-hood over the front of the engine as well as removed the engine cover between the two front seats, started it up, and started evaluating. After a few moments, I became vaguely aware that the engine note seemed to be slightly off, and I said so. He said, “You are used to car engines, this is a truck engine which has slightly different heads and a different cam.” Maybe, I thought to myself, and I started pulling plug wires starting at the #5 cylinder (which in my experience has been the weakest cylinder on the old small block Mopar engines). I pulled several plug wires off and each rewarded me with a proper drop in engine RPM and smoothness. He kept insisting that this was a truck engine and they simply run a little rougher than car engines. So, I gave up and said, “Lets take it for a spin.” Sure enough, after a couple of miles, the engine started bucking severely at virtually any positive throttle setting once in second gear.
What was wrong with this engine?
Best Regards,
Shipo
Hmm...I'm not going to answer but I will say this could be tough, because bucking only when warm relates more to fuel issues (i.e., engine running on choke is over rich, compensating for extreme leanness when operating at normal temperature), BUT bucking under load often relates to ignition. I say under load because there is no load in first gear, but most likely there would be in a motor home in second gear.
As it turned out, the problem was not ignition related.
Best Regards,
Shipo
A valve problem?
I've seen alot of motor homes with the Chrysler engines eat the exhaust valves and depending on how advanced it was, it may not show itself until warm.
After testing the plug wires, I pulled off the air-cleaner (I cannot remember why), and each time the engine bucked, a 2 foot tall column of flame came shooting out of the carb (torching the arm-hair off my arm the first time it happened).
Best Regards,
Shipo
Either the intake valve has a problem, a rocker is toast, possibly a valve spring or a long shot in the dark, the air cleaner was clogged?
As it turned out, I never actually pulled all eight plug wires during the initial test when the engine was at idle; I had given up after 7. As soon as I saw the column if fire come up from the carb, I reached down and pulled the #6 wire, and suddenly, the engine seemed to be running perfectly again (albeit on 7 cylinders). When I told the owner that the #6 intake valve was burned, he did not believe me. We blew a compression test and he still did not believe it even though all of the other cylinders were ~80 pounds and #6 was zero. A year later, I was back visiting, and I asked about the engine. He said, "Wait there for a moment." When he returned, he had an intake valve in his hand which was so burned, it looked completely oval!
A little investigation revealed that there had been a batch of motor home chassis (several hundred) complete with drive trains and instrumentation that had been sold to Winnebego (sp?) during the early 1980s, that had sat in a field (in Indiana I think) for a couple of years while the company worked itself through some financial difficulties. As it turned out, Winnebego sold many of those chassis to other builders of motor homes, many of which developed some form of engine problem (mostly valve problems) within a year or two of being sold to the final buyers. In the case of this one, if I remember correctly, the engine and chassis of this unit had been built in either 1983 or 1984, but was delivered as a 1986 vintage motor home. Two years and 26,000 miles later, and the result was the burned intake valve, and of course, by then, long out of warranty as far as Chrysler was concerned.
Best Regards,
Shipo
here's the problem.. guy is driving it down the hwy, all of a sudden, engine dies like it ran out of gas, pull's over, hits the key, starts right back up.. go down the road again, no power loss and runs normal but, does it again in less than 1/4 mile. pull the fuel line, electric fuel pump in tank is pumping plenty of volume.
any ideas?
bob in jville.
Do the guages all drop off? Do lights stay on when this happens?
Is the fuel pump working when the engine dies?
What is the voltage when this happens? Are all the connections, ground and power good?
Just a start.
Best Regards,
Shipo
-Andrew L
good job.
bob in jville.
If I may .....
This happened to me a couple of years ago in a 1992 300E. Driving down the road, suddenly the sun roof opens by itself. Later it would begin to open and sometimes close without any clues from me, the driver. After a while of this sporatic demon, the driver's side window did the same. So now I have the sun roof and the window under some demon's control.
I'd go into the shop and of course nothing would happen. I would tell them my car was possessed and they would look like I was some crazed maniac.
which oil is thicker, a 50w motor oil or 90w gear lube?
Best regards,
Shipo
Now that I think about it, I guess it does not matter, because if you listed the "Label Weight", then its equivilant SAE weight would be 25W, whereas if you listed the SAE weight, it would be 50W, either way, the gear lube is thicker.
Best Regards,
Shipo
Everything is fine for about a week, and the weather does in fact turn markedly colder, quite severe actually. But his truck starts fine and runs well as long as he warms it up for a while. He does notice a drop in gas mileage though, which he attributes to longer warm up, etc.
One day, about a week after the oil change, he notices that a) his valve cover gasket and breather cap seem to be leaking a bit, and that his engine's dip stick shows way overfull. He goes back to the quick lube place and says that there is too much oil in the crankcase and that the engine is trying to blow it out. They check it and agree. They say they "read the chart wrong" and put in 7 quarts instead of 5. So they drain out enough oil to get the proper reading.
So the oil now reads level and he's on his way again. About a week after that, while cruising at freeway speeds up a long hill, his oil light goes on. He has the car towed to his garage and they tell him he has an audible lower bearing knock and that the engine should be torn down.
What went wrong here?
here a chart i have on my site that might explain help to clarify it. might take a minute to download.
http://www.bobistheoilguy.com/visc.html
After digging around, I have been unable to find any single manufacturer of engine oils and gear lubes that produces a 90W gear lube that has a viscosity that is as high as their 50W engine oil. That said, all of the lubricants that I looked at, fell within the range shown on your chart.
Good question.
Best Regards,
Shipo
The problem is, I cannot understand how said heavier 5W oil (which is still pretty light) could cause the problems you describe, maybe I am not on the right track. Anyone?
Best Regards,
Shipo
Inspection shows that when the car is "idling" exhaust fumes are blowing out of the oil filler pipe - this looks serious!
However, removing 1 nut and replacing 1 cheap part fixes the problem - total time taken ± 30 minutes. What was that part?
No?