Nissan Pickup overheated from lack of coolant - need to assess possible damage

Maintenance/Repairs
1

I work for for a non-profic organization. We have a 95 nissan 2.4L pickup, and one of the guys drove a fair distance while overheating because of a coolant leak. He did not quite make if back before the truck died. At first I offered to do the work on it thinking maybe it just needed a new head gasket and some machining on the head surface. But I did a compression test and 2 cylinders were around 30 and the other 2 around 40psi. Also there is coolant in the oil.

Given that the pressure is so low do you think there is much of a chance that the head is not completely warped and needs to be replaced. Is it unlikely that there would be damage to the bottom of the engine, cylinder walls, pistons or warped block? I know one cannot say for sure until the head is removed but I would like to avoid wasting the time because if the truck needs a new head or worse they are gonna just junk it.

Thanks.

2

It’s likely that there is cylinder wall and piston/piston ring damage.

Revisit that compression issue with a wet test and odds are those horribly low numbers will take a huge jump upwards. This would mean the rings/cylinder walls are wiped.

Coolant in the engine oil can also wash out cam lobes, crankshaft journals, and crank bearings along with the timing chain.
Sounds like it’s barbecued to me… :frowning:

3

By the time things bind up from oil depletion tight enough to stop the engine, it’s a safe bet that there’s serious internal damage to everything that was supposed to ride on oil.

I think your best bet is to either find a replacement vehicle or look for a boneyard motor. The current engine is history.

4

I did a wet test and all cylinders stayed at about the same compression. So that nis a good indication that the rings and piston walls are ok. Probably looking at a new head.

5

@tilopa‌

When you have the head on a bench, put a straightedge on it and measure the warpage

Please keep us updated

A good machine shop can “clean up” a head . . . to a certain extent

6

Did not get a chance to follow up on this until now… I pulled the head and checked warpage on the block. The block is fine. Took the head to a machine shop and they resurfaced the deck and honed the valve seats, all for about 120$. Put it all back together and the truck is running like a champ.

7

Congratulations on a job well done and sincere thanks for the followup.