Toyota landcruiser 100 series V8 is running on 4 cylinders, low compresion in 4 and good

Adrian V

compression in 4.? Had the heads off and the clearance was reset, couldn't find a thing wrong with it. Any ideas?? The car just started losing power while driving and stalling. only traveled 150,000 km. It runs on Gas/Petrol.

Cheryl W

There is not enough information to help you diagnose the problem.































Are the 4 cylinders with the poor compression all on the same bank/side? Is the compression still low on those 4 cylinders after replacing the head gaskets and re-tightening the head bolts?































Were the cylinder walls inspected when the heads were off? (You should be able to see the cross-hatch machining on the cylinder walls without any vertical scratches.)































Did the engine ever over-heat? Has there always been enough oil in the engine and has it been changed at the correct intervals?































If the head gaskets were replaced and torqued down properly, all 4 low-compression cylinders are on the same bank/side and the cylinder walls looked good, it would appear that you have a cracked head (or more than one crack). This usually happens because the engine was over-heated.































As a further test, put oil in one of the cylinders with the poor compression, and retest the compression. If it goes up, the problem probably has to do with the piston rings. Repeat for all the cylinders with low compression.















































Good luck.