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My '65 suddenly started running bad today

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mgless

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I have a 65 Sprite with a 1098 block, 1275 head. It was rebuilt by the PO about 7 years ago and has maybe 3000-4000 miles on it. I just got back from a 600 mile trip with the car last week and it ran great.

I was driving it this morning and was about 15 miles down the road. The car was warmed up to about 175 and I had around 60psi oil pressure. I was driving down a state highway at 55mph and I noticed something seemed off all the sudden. Then when I pushed the accelerator, the car made what sounded like "knocking."

Temp and oil gauges still looked good, so I limped it to my folks house about a mile away going about 15mph. Any faster, or up any inclines, and the engine would make the "knocking" sound. It will start back up again, but it's running rough and won't idle for very long before it dies.

I've done lots of work to the car over the years, but I've never had to touch the drivetrain... so I'm at a bit of a loss as to where I should even start. Point me in the right direction?
 
So does it have oil in it?
 
Points gone bad? Rotor Bad - there were a bunch of crappy rotors out there. Timing slipped? The "knocking" scares me though. Let's got through the simple stuff fuel, spark, air first before we jump to the hard / expensive stuff. Someone else will join in shortly I'm sure.
 
Knocking might not be the right word. A loud clatter perhaps? I used to get a similar sound every once in awhile under heavy load, say while climbing a hill in 4th gear, just before downshifting to third. Except now it does it under very little load. I can make a video of it tonight if that would be helpful.
 
Does it make rattle when idling? Is it hard to start?
 
So are you using Premium Fuel. These engines don't run on 87 Octane, 93 or 94 if you can find it.
 
Trevor Jessie said:
Does it make rattle when idling? Is it hard to start?
Click to expand...

I only tried restarting it once, but it took a few cranks and some gas to get it going whereas it usually starts easily. It ran for about 10 seconds then quit. It didn't make the rattle sound when idling but it was definitely running rough.

I am using no-ethanol premium fuel. Usually 91 octane.
 
Based on your description, something sounds bad wrong. The only thing that come to mind that might be simple is if the distributor popped loose. Check the dizzy and the static timing.
 
Timing chain???? Don't know if the chain can jump on a 1098 but do know they were single row rather than double on the 1275.
Static timing check should tell for sure especially if the distributor is tight and hasn't moved.

Kurt
 
Ack... Sounds to me like it is time to pull the engine apart.
 
That's what my 1098 did. ....

For a year or so mine would ping as if running on regular instead of premium, or as if the time were too far adavanced... I kept dialing back the timing a couple of clicks on the dizzy trying to get rid of it... and never quite could. I had the dizzy rebuilt (by Jeff) and still had problems.. when it did go away the timing was actually slightly retarded, so I put it back to "right" and started the process all over.... then when I was out for drive, I got the same sounds and lack of power as you have. It sounded like it was running on 2 or 3 cylinders instead of 4, kinda clattery.

let me know what you find when you tear it apart. I THINK i sucked a valve... ... or blew the head gasket.......or holed a piston........ I still have the engine sitting in the garage.
(I have since replaced the engine from the air filter to the exhaust tip)
 
Compression readings from front to back: 180, 170, 20, 15. I'm assuming blown head gasket between the back two. I've never torn into an engine before, I guess there's a first time for everything!

A few things I'm uncertain about... I have a 1098 block and 1275 head. Do I use the 1275 gasket? What else would I need to purchase to replace the gasket?

Since the engine was running normally beforehand and was never overheated, can I assume it was just a cheapie head gasket that the PO used rather than some other problem that caused it? The engine has less than 5000 miles since the rebuild.

I have the Haynes and the 1275 shop manual -- are there any other noob-friendly videos or guides out there?
 
I hate to say it but, just a blown head gasket is not going to make that kind of noise... :grey:

If it were mine I'd:
1. Not run it again, (it sounds like there's loose metal slapping around in there on your video)
2. Remove the cylinder head
3. Drink beers
 
And then after you've pulled the head you probably need to add more beers. 20 and 15 lbs sounds like way beyond a head gasket failure. At this point time to get out the wrench and sockets and start disassembly. Head is only torqued to 40 lbs or so and should be fairly easy to get this one apart. You know after those compression #'s that it needs to come apart. Like removing a Band Aid, thinking about it is worse than the actual event. Beside, you're missing some prime driving season. Others will need to answer the head gasket question.
 
The metal slapping sound turned out to be the bumper bracket. It was rattling from the rough idle. :shame:

When I push in the bumper, the engine sounds about what you'd expect it to sound like running on two cylinders.

AN5Sprite said:
I hate to say it but, just a blown head gasket is not going to make that kind of noise... :grey:

If it were mine I'd:
1. Not run it again, (it sounds like there's loose metal slapping around in there on your video)
2. Remove the cylinder head
3. Drink beers
Click to expand...
 
mgless said:
A few things I'm uncertain about... I have a 1098 block and 1275 head. Do I use the 1275 gasket? What else would I need to purchase to replace the gasket?

Since the engine was running normally beforehand and was never overheated, can I assume it was just a cheapie head gasket that the PO used rather than some other problem that caused it? The engine has less than 5000 miles since the rebuild.

I have the Haynes and the 1275 shop manual -- are there any other noob-friendly videos or guides out there?
Click to expand...

Yes, you need to use a 1275 head gasket. You always match the head gasket to the head. You should use the best Payen black head gasket. I think the number is BK450P. It would also be a good idea to at least use 1275 head studs and torque settings, but I would go with ARP head studs. The couple other things to check is that you do not have any recession of the brass plugs in both the head and the block where the water jacket holes are. Your head swap requires relocation of the water jacket holes in the block to match the head, so you'll want to check that and make sure it was done right.
 
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