4.2. Check of compression pressure in cylinders and parameters of motive oil
Check of compression pressure in cylinders
Results of check of compression pressure in cylinders allow to define the general condition of components of the top part of the engine (pistons, piston rings, valves, laying of a head of cylinders, etc.) and to qualitatively estimate degree of their wear. What is especially important, the analysis of information obtained as a result of check allows to narrow a range of the possible reasons of falling of a compression in cylinders, having rather precisely tied refusal to violations of functioning of quite concrete components, whether it be piston rings, valves, their saddles or laying of a head.
The engine has to be heated-up up to the normal working temperature, and the rechargeable battery is completely charged.
- Begin with a clearing of candle niches (blow them compressed air as which source in this case the ordinary bicycle pump perfectly will approach). The main objective is prevention of hit of garbage in cylinders during performance of measurements.
- On DOHC 1.0 and 1.2 engines of l separate both sockets of the control unit of the engine and remove the ignition module.
At the same time ignition has to be switched off.
- On DOHC 1.4 and 1.6 engines of l uncover VV of wires. For this purpose uncover a maslozalivny mouth and then again establish it.
- Separate sockets of spark plugs. For OHC 1.2 and 1.4 engines of l special nippers are used (for example, HAZET 1849). At separation of sockets it is necessary to undertake only sockets, but not conducting at all. On l DOHC 1.4 and 1.6 engines sockets of spark plugs are separated by means of the special tool which is on one of sockets. Turn out candles a special candle key.
- On the C14NZ engine separate the multicontact socket of the coil of ignition.
The multicontact socket of the coil of ignition on the C14NZ engine
- On all engines, except C14NZ X10XE and X12XE separate the multicontact socket of the module of ignition of DIS.
- On petrol engines 1.2, 1.4 and 1.6 of l take the relay of the fuel pump (shooter). Thereby the situation at which during start of the engine injectable fuel in not burned down look can come to the catalytic converter is excluded. The relay is in salon behind facing of a rack of A, on the right below. On diesel engines disconnect an electrical wiring from the switch on TNVD.
Extraction of the relay of the fuel pump will allow to cut off power a power supply system of the petrol engine
- Turn the engine a starter to remove the remains of air-fuel mix and I sit down.
Previously transfer the transmission to neutral situation and cock the parking brake. At the same time do not bend down over the engine not to be traumatized from emission of particles of soot.
- Establish компрессиометр in a candle opening of the first cylinder, - it is preferable to use a nozzle of carving, but not clamping type to connection of a kompressiometr. Do not forget to open during check against the stop a butterfly valve.
In diesel engines extent of compression is much higher, than in petrol therefore for check of compression pressure it will be required special компрессиометр with a range of measurement not less than 40 atm. Kompressiometr is rolled by the transitional nozzle in a glow plug opening.
- Ask the assistant to press the accelerator pedal and to hold it in the course of conducting check.
- Scroll a starter during 4 with or so much how many it is necessary in order that on a kompressiometra there were no pressure jumps. On the serviceable engine pressure has to increase quickly enough. The low pressure on the first step which is followed by its gradual increase on the subsequent speaks about wear of piston rings. If at a further provorachivaniye of a shaft pressure does not rise, it can be regarded as the evidence of leakages of valves or violation of tightness of laying of a head of cylinders (also the probability of existence of cracks in a head is not excluded). The congestion of deposits on working facets of plates of valves can also lead to decrease in compression pressure. Write down the maximum indication of a kompressiometr.
- Repeat the procedure for the remained engine cylinders. Compare results to standard requirements (see the Head Dvigateli). Speed of a bent shaft when checking has to be not less than 300 rpm for petrol engines and not less than 200 rpm for diesel.
- At excessively low results of measurement fill in in each of cylinders through a candle opening of a little motive oil (two-three teaspoons) and repeat check.
- If addition of oil leads to increase in pressure, it speaks about wear of piston rings. If the compression does not increase, leakages of valves or violation of tightness of laying of a head are the reason of its decrease. Leakages of valves can be connected with a burn-out of their saddles, either a deformation/burn-out or mechanical damages of working facets.
- If pressure of compression is equally underestimated in two next cylinders, then with high degree of probability it is possible to speak about violation of integrity of laying of a head within its crossing point between these cylinders. Presence of cooling liquid at motive oil will confirm this assumption.
- If pressure in one of cylinders is about 20% lower, than in other and it is followed by violation of stability of turns of idling, it is necessary to estimate degree of wear of cams of the drive of the corresponding valves on the camshaft.
- Unusual overestimate of compression pressure usually is a consequence of an excessive nagaroobrazovaniye in combustion chambers. In this case the head of cylinders has to be removed for the purpose of carrying out decarbonization.
- At excessively low results of measurements, and also in case of violation of uniformity of distribution of pressure between cylinders it will be useful to hold testing of the engine for leaks in the conditions of a workshop of car service. Such check will allow to define precisely a source of leak and to estimate degree of its gravity.
- After the end of measurements establish all candles of an ignition/incandescence and connect to them an electrical wiring.
- Install all being removed components as it should be, the return to an order of their removal.
Check of the block on leaks
During this check are defined exit speed from cylinders of the compressed air pumped in them and directly the place of leaks. This check is an alternative to check of a compression. Moreover, from many points of view, it is much more effective as visually it is simpler to reveal a leak source, than to comprehend results of measurement of a compression.
The equipment necessary for check on leaks, is not among public therefore performance of this check should be entrusted specialists of the service center.
Measurement of temperature of motive oil
Determination of temperature of motive oil is important for performance of various adjusting works. Temperature should be taken at distance 1 cm over the case pallet.
- For measurement of temperature insert the measuring probe into a guide of the probe of level of motive oil, rest it against the case pallet, and then raise by 1 cm.
- To exclude suction of air through a probe guide, condense its opening with a rubber stopper.
- Oil 80 temperature hail. corresponds to the working temperature of the engine above.
At an engine overload temperature of oil can reach value 150 a hail.
Check of pressure of oil
- Warm up up to the working temperature.
- Switch off ignition and disconnect an electrical wiring from D/V of pressure of motive oil.
- Turn out oil pressure D/V. It is located:
- on petrol DOHC 1.0 and 1.2 engines of l – from above heads of cylinders, over the water pump;
- on petrol engines 1.2, 1.4 and 1.6 of l – sideways from the oil pump, over the CKP sensor
- on diesel engines – on the face party of the engine, near an oil filter.
D/V of pressure of oil of petrol engines
- Screw the manometer in a carving opening of D/V of pressure of oil. HUNDRED Opel apply for this purpose KM-135 hose with the KM-498-B manometer.
- Start the engine and let's it work on single turns.
- Consider indications of the manometer and compare them to requirements of Specifications in the Head Dvigateli. If necessary check an oil contour for leaks.
Turn out the manometer, establish new D/V of pressure of motive oil with new copper laying and tighten it with effort of 30 Nanometers. Connect an electrical wiring to the sensor.