'99 Q45T with a rod knock ... can I???

[truckmen]

Hello all,

I recently acquired a '99 Q45T with a rod knock.

The engine started and after throwing some fresh gas, got it to run steady.
I discovered the very loud "rod knock" sound. However, no "engine check light" comes on nor does the engine run all that rough.
I revved up the motor in park to ~2000 RPM and the "knock" speeds up in sync. As the engine drops back down to idle, the knock gets very loud during part of the idle-down. My spotty experience tells me that this is a rod knock. Could anyone concur? I know that oil pumps can also make a similar sound when they "go out".

Can I somehow just drop the oil pan without removing the engine to access the crank and determine for sure that it is a rod. I do not have a lift but I DO have floor jacks and jack stands.

If this were your car, would you just go and find a replacement motor or fix the current one?


Ralph

[BadQ45t]

How many miles on the motor and do you know anything about the history of it? The internals of the motor are completely bullet proof, it is just O2 and knock sensors and coil packs that seem to be the only things that people replace...maybe a valve cover gasget as well, but the internals I have hardly seen anybody with an issue with these.

[Skibane]

Can I somehow just drop the oil pan without removing the engine to access the crank and determine for sure that it is a rod.

If you can borrow or rent a borescope, you might be able to take a look through the oil drain plug.

Draining the oil would also give you an opportunity to see if anything "interesting" is suspended in the old oil. Ditto for cutting open the old oil filter.

I definitely wouldn't just slap a different engine in there without first knowing exactly what condition the current one is in.

It's not unknown for these engines to bend a rod when a fuel injector gets leaky enough to hydrolock a cylinder.

[truckmen]

How many miles on the motor and do you know anything about the history of it? The internals of the motor are completely bullet proof, it is just O2 and knock sensors and coil packs that seem to be the only things that people replace...maybe a valve cover gasget as well, but the internals I have hardly seen anybody with an issue with these.

Hello Jeff!

Please forgive my late response;
I have almost no history on my Q45T. The odometer shows 187600 and it looks like the original engine.
Hey, I see you are located at Half Moon Bay. I hear that is a beautiful place. I am on the other side of the country near Bar Harbor, Maine.

Ralph in Maine

[truckmen]

If you can borrow or rent a borescope, you might be able to take a look through the oil drain plug.

Draining the oil would also give you an opportunity to see if anything "interesting" is suspended in the old oil. Ditto for cutting open the old oil filter.

I definitely wouldn't just slap a different engine in there without first knowing exactly what condition the current one is in.

It's not unknown for these engines to bend a rod when a fuel injector gets leaky enough to hydrolock a cylinder.

Hello Skibane!

After reading your post, I did some searching and pricing for a bore scope also reading the associated reviews. I seems like many people had stated that once they obtained wondered how they got along without one. I believe I will get one later next week. I also do not want to go with another engine either. I think my main concern is the possibility of just dropping the pan without having to pull the engine. I think I am a bit concerned with all of the components, hoses, wires, etc. that would ave to be shifted for the engine pull. However, I DO have an engine hoist but no lift other than a couple of shop jacks.

Ralph

[BadQ45t]

Yup, Half Moon Bay, CA where we don't have summer (it is 64 degrees outside and 85 degrees only 10 miles away). given how many miles are on that motor you are probably looking at coil packs, knock sensors and a few other things if they were never done. I suppose if the person that owned it previously was the type that did oil changes when the dummy light came on you might have internal damage.

If you can at least get the opinion from a mechanic it would at least be worthwhile to have them listen to the noises. I don't think you will find a very rich rebuilt engine market for our cars (unlike your J30 which has tons of rebuilts on the market), very few were sold. You cannot even find aftermarket shocks/struts unless you import them from Japan. But that is part of what makes this year car cool, nobody knows what it is

I would probably say given how stout the engine build is overall (unlike say a GM Northstar of the same period) that fixing it would be that bad.

[truckmen]

Yup, Half Moon Bay, CA where we don't have summer (it is 64 degrees outside and 85 degrees only 10 miles away). given how many miles are on that motor you are probably looking at coil packs, knock sensors and a few other things if they were never done. I suppose if the person that owned it previously was the type that did oil changes when the dummy light came on you might have internal damage.

If you can at least get the opinion from a mechanic it would at least be worthwhile to have them listen to the noises. I don't think you will find a very rich rebuilt engine market for our cars (unlike your J30 which has tons of rebuilts on the market), very few were sold. You cannot even find aftermarket shocks/struts unless you import them from Japan. But that is part of what makes this year car cool, nobody knows what it is

I would probably say given how stout the engine build is overall (unlike say a GM Northstar of the same period) that fixing it would be that bad.

Hello again, BadQ45T,

Thank you for the info. Okay, I haven't yet purchased the bore camera and might hold off (budget constrains, you know), and will price the other items. I can tell you that I am not very confident about mechanic for the Q45 "around these parts" (Mid-coast Maine) so, I will think through what to do. Whatever I do, I will make sure to follow up here on the forum.

Ralph

[Infinitiguy19]

If I were you I would take a stethoscope and put it on the oil pan while the engine is running. You should head a knocking sound strongly if it were the bottom end.

[BadQ45t]

Is this your only car or do you have another...as long as it isn't your only piece of transportation then just keep messing with it.

[truckmen]

Is this your only car or do you have another...as long as it isn't your only piece of transportation then just keep messing with it.

Good morning, BadQ45T,

Nope, it's a car we picked up for a very low price, the previous owner (and we) thinking the motor was seized. I might get to the car today to resume diagnosing the problem.

Ralph

[BadQ45t]

Cool, so you can slowly figure out what is wrong. Once you get it running it is a very nice car.