MAN city bus: worn diesel regained compression, no teardown

Compression recovered on every cylinder, the weakest one caught up, the engine evened out. MAN - 202 bus, O.D.A.X LTD, Israel. Israel · 2005. 7.7-25 %.

O.D.A.X LTD, XADO representative in Israel · Mordechai Baycher · municipal fleet bus

Israel · baseline measurement before 09.01.2005 · treatment 06.02–16.02.2005 · check measurement 01.03.2005

PRODUCTXADO compoundthree-stage treatment over ten days, without taking the vehicle out of service

TEST OBJECTMAN - 202 busdiesel engine, 6 cylinders, 141 hp · mileage 412 213 km

DOCUMENT TYPEReport by the XADO
representative in IsraelO.D.A.X LTD · company seal impression

Key results

compression evened out across the cylinders

↑7.7-25%

compression by cylinder, 22-26 → 27.5-28 bar

VEHICLE	MILEAGE AT START OF TRIAL	WHAT WAS MEASURED
MAN - 202 bus, 6-cylinder diesel, 141 hp	412 213 km	Compression in each of the six cylinders, bar

Compression by cylinder — before and after treatment

CYLINDER	BEFORE, BAR	AFTER, BAR	CHANGE
1	25	28	+3 bar
2	25	28	+3 bar
3	25	28	+3 bar
4 — weakest	22	27.5	+5.5 bar
5	25	28	+3 bar
6	26	28	+2 bar
Spread across cylinders	4	0.5	−3.5 bar

Baseline measurement taken 09.01.2005, control measurement 01.03.2005, 13 days after the third stage. All six cylinders reached 27.5-28 bar.

What this means

The engine came to treatment with 412 213 km on the clock and sagging compression: the weakest, fourth cylinder held 22 bar against 26 bar in the strongest. A spread of 4 bar is a sign of a worn cylinder-piston group: the engine runs unevenly and loses power. The three treatment stages took ten days, and the bus stayed on its route throughout — between the first and the last stage it covered 810 km. The control measurement gave 27.5-28 bar across all six cylinders: the weakest gained 5.5 bar, and the spread narrowed to 0.5 bar. Even compression means the sealing of the cylinder-piston group has been restored, and it cannot rise above the factory nominal: bringing every cylinder to one level is the maximum achievable. Obtained without dismantling the engine, on a vehicle in normal service.

The results apply to the diesel engine of a MAN - 202 bus with over 412 000 km of mileage; on other equipment and with a different condition of the components the figures may differ. The treatment was carried out and the result reported by the XADO representative in Israel — O.D.A.X LTD. The original document is published in full and available for download.

Current equivalent

Revitalizant gel for diesel enginesDiesel engines
Revitalizant gel for cylinder restorationEngine cylinders, deep wear

How such units are treated: Diesel engine Cylinder-piston group

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