Can the distributor cap and rotor being bad cause long term issues even after replacement?

We bought a 1999 GMC Savanna cutaway. It’s…actually an old Blue Bird school bus. It is the vehicle of my dreams in many ways, because we have too many kids to make a mini van work with car seats. About eight months after we bought it, we threw a rod in the driveway and replaced the motor with a refurbished one with a one year warranty. If certain paperwork had been completed and the work inspected, it would have been warrantied for three years, but apparently no amount of nagging on my end could make that happen with my husband, so it was not done. This occurred about fourteen months ago.

It was never quite right…the timing felt a little off and recently lots of things felt off. My husband was driving it home three days ago when the oil pressure dropped and the engine shut off. He managed to coast to the side of the road and then my father in law towed him home (not far). The next day we took it into the shop expecting a huge amount of repairs, and yet they just replaced the distributor cap and it fixed the issues we had been having for months (and that the shop had been previously unable to figure out). Our mechanic said the gears and stuff on the bottom of the cap (so the rotor I think?) were sheared almost all the way off.

My husband changed the oil and right now, it runs like a dream. Our question is: will running it for so long with a bad cap and rotor have caused long term damage? My father in law and uncle in law think that the metal pieces got into the engine and will destroy the valves? They are leaning heavily on my husband to sell it now and get a “reliable car.” The only other vehicles that will fit us all are those huge passenger vans, and to be honest…I don’t want to owe more for a van than I do for my house, and I don’t want to drive a huge van that still doesn’t have enough cargo room for a stroller and a cooler if we go somewhere for the day.

So what can we expect as far as long term damage from this problem? Should I keep the bus?

Would you feel much safer if the mechanic had lied and charged you hundreds more claiming that he had repaired broken parts in the block?

No! broken pieces in the distributor won’t be lurking to break something in the future. The distributor drive gear can damage the engine but if that had happened the camshaft would have been replaced to get it running so smile and enjoy driving the Blue Bird of Happiness.


I trust our mechanic. He also does a lot of work for our farm stuff and he goes to our church, so he’s good people. I am way more easy going than everyone else about this situation-of course I need my kids to be safe but I think of it a lot like an adventure.

Thanks for affirming what I thought! And thank you very much for the new nickname-she will forever be known as the Blue Bird of Happiness!

Anything that breaks off under the distributor cap cannot get into the engine. It could be easily removed as well. If the gear on the bottom of the distributor shaft was the problem, broken teeth could get into the engine.

If it was the gear though, it is held in place with a sheer pin. That is the “weak link” that intended to break first and the pieces would be held captive by the gear and the distributor shaft. It would have stopped the engine almost immediately but very unlikely to do any damage.

My opinion based on your provided information is “it’s cheaper to keep her”.

It was the gear teeth that were sheared off.

If you are sure the teeth were sheared off, it is still unlikely that it would do any damage. There is a screen over the oil pickup tube that would block any but the smallest pieces. Anything that is small enough to get through the screen will be too small to hurt the oil pump. Next the oil goes to the oil filter and it will filter out just about anything over 10 microns in size.

I still think you don’t have anything to worry about, but I would be concerned that the teeth were sheared off instead of the shear pin. Maybe someone used a hardened roll pin instead.

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No experience with bus engines, except that as a kid I rode to school on a Blue Bird bus many times. Blue Birds – at least at that time – made very nice school buses; the other kids and the bus drivers using different bus routes were envious of our shiny, brand new Blue Bird.

Now on to your problem. On many engines there’s several gears involved which allow the camshaft to drive the distributor shaft, which in turn drives the oil pump. The oil pressure drop might imply there’s a problem with all that. Removing the distributor and taking a look-see at its shaft would be the first step if that was thought to be the problem. It’s also possible the oil pressure drop was simply a result of the engine stopping due to lack of spark from the distributor cap/rotor problem. Replacing the distributor cap and rotor is a routine maintenance item on distributor equipped cars, often done as part of a normal tune-up.

It’s a GM van cab with a bus body attached @George_San_Jose1. The engine was likely a 350 V-8. And while we don’t know the details of what the shop found if the mechanic quickly found and repaired the distributor and got it running well at a surprisingly cheap price it’s likely he was well qualified and honest. These days that is becoming a rare find.

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This is the place where anyone can say about anything-related or not. But the nursery rhyme about the lady who lived in the shoe and had so many kids she didn’t know what to do, came to mind. I had a guy working for me that had a lot of kids and not much money (his own fault). He always drove well used Suburbans to fit them all in. So just a polite suggestion that maybe at some time, consider something other than a school bus. A lot easier to park. Even something like a transit van sometimes can be had pretty cheap. But I guess I wouldn’t worry about the distributor “if” there were particles and they were cleaned out. But I’m not a mechanic.

We actually did look at suburbans. The issue is that so few vehicles are safely equipped to have a large number of car seats installed-even if they fit three across, often there are not top tethers to safely install seats. This holds true on many, many family vehicles (for example, even large twelve or fifteen passenger vans do not allow for seats to be installed in many seats due to not being properly equipped with top tethers). So while it may be an option in the future, due to the car seat issue and the ages of our children, it isn’t really feasible right now.

And I wanted to comment that I’m perfectly fine knowing what to do with my children, thank you very much. My question was mechanical in nature, not a request for your opinion on large families.

Why are you thin skinned about having a large family? I consider it a blessing from God. My wife and I were both only children and now if we could all get together there would be 25 of us.