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What are some important things you should NEVER do when rebuilding your engine?

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SheNeverRuns

Probationary Member
17
5
Dec 6, 2023
rockaway, New_Jersey
Hey guys right now I’m rebuilding my first DSM engine. I have the head off and getting ready to reassemble everything. What are somethings I should not do compared to other engine builds?

Also what would you do since I have the engine apart right now? I am not taking the pistons out since they are newer Weisco’s and Eagle rods.

Reason for me taking it apart was timing belt was very sketchy, small oil leak, cams were very aggressive and the 6 bolt swap wasn’t done correctly. I wanted to insure myself I have a good healthy engine for the next few years at least !

Thanks everyone !
 
#1 do not do while rebuilding engine: Smoke crack.

#2: don’t use a roloc disk on the surface of the block. Use a plastic razor blade to remove the old gasket material.

#3: don’t do meth either.
Way to take the fun out of it, sheesh.
 
Make a list of every rag you shove in the block, head or intake so that they all get removed before reassembly.
 
Somebody will disagree with me. I have a set of lisle carbide scrapers I use for gasket removal. You absolutely need to know what you're doing or you can do a lot of damage in a hurry. I've used plastic razor blades, regular razor blades etc. Nothing has compared to these.
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Stuff you should never do...
Don't turn the crank or cams with the belt off. You need to know relative position if you do.
 
Never spin the motor backwards and confirm the oil pump is primed and builds pressure before firing it over for the first time.

RTV is your friend - not a cake frosting. Use as little as possible.

After a heat cycle - re-check every bolt you can put a tool on - especially if there is new powder coated parts involved
 
I've rotated the motor backwards for aligning if I shoot past, but I've never understood if it's just an old wife's tale or not for full rotations. I've never seen a belt jump the cam gears by rotating the engine backwards.
 
I've rotated the motor backwards for aligning if I shoot past, but I've never understood if it's just an old wive's tale or not for full rotations. I've never seen a belt jump the cam gears by rotating the engine backwards.
This is more about preventing the oil pump from loosing prime. Spinning the engine backwards will suck air into the pump, and I have jumped the AC belt off one rib of the tension er pulley going backwards.
 
You can spin the engine any way you want with the timing belt off as long as all the valves are closed.
You don't need to pre-prime the oil pump. Guys....what do you think happens when you leave your car sitting for weeks...months without starting? Do you pre prime the oil pump? You should already have assembly lube on vital journals. Oil pressure should be observed within 3 seconds after cranking.
 
You can spin the engine any way you want with the timing belt off as long as all the valves are closed.
You don't need to pre-prime the oil pump. Guys....what do you think happens when you leave your car sitting for weeks...months without starting? Do you pre prime the oil pump? You should already have assembly lube on vital journals. Oil pressure should be observed within 3 seconds after cranking.
Don't need to pre-prime? During a build you do. Presumably before the car is sitting for months, the pump was primed, and when the oil drains back to the pan there won't be air in the pickup tube. "Starting for the first time," you want to make sure the pump is pulling oil to the gears. Call me paranoid - but I crank for oil pressure after oil and filter changes.
 
You can spin the engine any way you want with the timing belt off as long as all the valves are closed.
You don't need to pre-prime the oil pump. Guys....what do you think happens when you leave your car sitting for weeks...months without starting? Do you pre prime the oil pump? You should already have assembly lube on vital journals. Oil pressure should be observed within 3 seconds after cranking.
Its a good way to check for leaks pre running of an engine. Here you can find leaks from pressure or seals by doing this method. Its a process of elimination and better to find now then when the engine is put together and then needing a breakdown to find a seal has not taken or something.
 
Letting your vehicle sit in the garage for a week is the same as letting the engine sit on the stand for a week, or even longer. The oil will drain from the pump but will keep enough of a coating on the gear meshing to provide that suuuuuuuuuction you need when you start it up (which is the same as why we pack the gears on assembly).

The bearings won't lose their oil as it's trapped. So, it's really about having that available pressure sooner right after startup, as the combustion definitely exerts more pressure against that film than just rotating.

I certainly don't take my timing belt off and prime the pump every time I want to drive the car on just weekends. Nor do I attempt to prime it before by cranking for 10 seconds prior.

There's interesting points to consider here, but everybody everywhere leaves their cars sitting for days at a time and they don't prime. After startup, my pressure is there within a second or two. That's probably enough for any of us.
 
I start my car every 45 minutes to make sure the oil pump is always primed. One time I fell asleep for an hour and had to take the timing belt off to prime the oiling system. Never again…

Joking aside. Don't overthink it people. Enjoy your car. It'll be ok.
Far out - man : 🥳
 
Since this has turned into an oil pump priming thread I figured I’d drop my .02.

On a fresh rebuild I will pack the oil pump gears with Vaseline. During assembly I will use plenty of assembly lube.

When finally ready to start I will pull the plugs and shut off the injectors and crank the motor over for 10 seconds at least twice before firing the car.

This is for a fresh motor first start-up only

-Daniel
 
Since this has turned into an oil pump priming thread I figured I’d drop my .02.

On a fresh rebuild I will pack the oil pump gears with Vaseline. During assembly I will use plenty of assembly lube.

When finally ready to start I will pull the plugs and shut off the injectors and crank the motor over for 10 seconds at least twice before firing the car.

This is for a fresh motor first start-up only

-Daniel
Vaseline is one i not heard of before being put into a pump. So thats to get pushed around the engine also and will pull oil up easier being packed vs full of air?
 
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LOL okay enough with the oil pump! I’ll prime her and let her crank for a few seconds before start up! Right now I have the head off and deciding whether to do the oil mod or not… it could use a little opening up but I’m afraid to get shavings near the valves or anything stuck in the oil gallery's since the head is ready to go back on, I also never knew what the oil pressure was before I took it apart since I had no sensor but I do now. I didn’t take the oil pump off yet or the case around it. When I spin the oil pully it doesn’t spin easily? But it doesn’t take any force. It does have the balance shaft delete if that has anything to do with how the pump feels. I’ll be uploading some pics in a little thanks for the help guys
 
Vaseline is once i not heard of before. So thats to get pushed around the engine also and will pull oil up easier being pacmed vs full of air?
It’s essentially the same as Jason said “petroleum jelly”. This is the tub I leave in my tool box drawer with my other ingredients that I’ve found useful. Last time I used it I was seating a fresh sending unit gasket and use it was a lube on o rings and such too.

-Daniel

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